diff --git a/.taskcluster.yml b/.taskcluster.yml
index d0911dfd3d..2a72f5a67d 100644
--- a/.taskcluster.yml
+++ b/.taskcluster.yml
@@ -6,301 +6,287 @@ policy:
     pullRequests: collaborators
 tasks:
     - $let:
-          taskgraph:
-              branch: taskgraph
-              revision: b6890b6736403f053b731cbd4aabe43819a14acf
-          trustDomain: mobile
+        trustDomain: mobile
+
+        # Github events have this stuff in different places...
+        ownerEmail:
+            $if: 'tasks_for in ["cron", "action"]'
+            then: '${tasks_for}@noreply.mozilla.org'
+            else:
+                $if: 'event.sender.login == "bors[bot]"'
+                then: 'skaspari+mozlando@mozilla.com'   # It must match what's in bors.toml
+                else:
+                    $if: 'tasks_for == "github-push"'
+                    then: '${event.pusher.email}'
+                    else:
+                        $if: 'tasks_for == "github-pull-request"'
+                        then: '${event.pull_request.user.login}@users.noreply.github.com'
+        baseRepoUrl:
+            $if: 'tasks_for == "github-push"'
+            then: '${event.repository.html_url}'
+            else:
+                $if: 'tasks_for == "github-pull-request"'
+                then: '${event.pull_request.base.repo.html_url}'
+                else:
+                    $if: 'tasks_for in ["cron", "action"]'
+                    then: '${repository.url}'
+        repoUrl:
+            $if: 'tasks_for == "github-push"'
+            then: '${event.repository.html_url}'
+            else:
+                $if: 'tasks_for == "github-pull-request"'
+                then: '${event.pull_request.head.repo.html_url}'
+                else:
+                    $if: 'tasks_for in ["cron", "action"]'
+                    then: '${repository.url}'
+        project:
+            $if: 'tasks_for == "github-push"'
+            then: '${event.repository.name}'
+            else:
+                $if: 'tasks_for == "github-pull-request"'
+                then: '${event.pull_request.head.repo.name}'
+                else:
+                    $if: 'tasks_for in ["cron", "action"]'
+                    then: '${repository.project}'
+        head_branch:
+            $if: 'tasks_for == "github-pull-request"'
+            then: ${event.pull_request.head.ref}
+            else:
+                $if: 'tasks_for == "github-push"'
+                then: ${event.ref}
+                else:
+                    $if: 'tasks_for in ["action", "cron"]'
+                    then: '${push.branch}'
+        head_sha:
+            $if: 'tasks_for == "github-push"'
+            then: '${event.after}'
+            else:
+                $if: 'tasks_for == "github-pull-request"'
+                then: '${event.pull_request.head.sha}'
+                else:
+                    $if: 'tasks_for in ["action", "cron"]'
+                    then: '${push.revision}'
+        ownTaskId:
+            $if: '"github" in tasks_for'
+            then: {$eval: as_slugid("decision_task")}
+            else:
+                $if: 'tasks_for in ["cron", "action"]'
+                then: '${ownTaskId}'
+        pullRequestAction:
+            $if: 'tasks_for == "github-pull-request"'
+            then: ${event.action}
+            else: 'UNDEFINED'
       in:
-          $let:
-              # Github events have this stuff in different places...
-              ownerEmail:
-                  $if: 'tasks_for in ["cron", "action"]'
-                  then: '${tasks_for}@noreply.mozilla.org'
-                  else:
-                      $if: 'event.sender.login == "bors[bot]"'
-                      then: 'skaspari+mozlando@mozilla.com'   # It must match what's in bors.toml
-                      else:
-                          $if: 'tasks_for == "github-push"'
-                          then: '${event.pusher.email}'
-                          else:
-                              $if: 'tasks_for == "github-pull-request"'
-                              then: '${event.pull_request.user.login}@users.noreply.github.com'
-              baseRepoUrl:
-                  $if: 'tasks_for == "github-push"'
-                  then: '${event.repository.html_url}'
-                  else:
-                      $if: 'tasks_for == "github-pull-request"'
-                      then: '${event.pull_request.base.repo.html_url}'
-                      else:
-                          $if: 'tasks_for in ["cron", "action"]'
-                          then: '${repository.url}'
-              repoUrl:
-                  $if: 'tasks_for == "github-push"'
-                  then: '${event.repository.html_url}'
-                  else:
-                      $if: 'tasks_for == "github-pull-request"'
-                      then: '${event.pull_request.head.repo.html_url}'
-                      else:
-                          $if: 'tasks_for in ["cron", "action"]'
-                          then: '${repository.url}'
-              project:
-                  $if: 'tasks_for == "github-push"'
-                  then: '${event.repository.name}'
-                  else:
-                      $if: 'tasks_for == "github-pull-request"'
-                      then: '${event.pull_request.head.repo.name}'
-                      else:
-                          $if: 'tasks_for in ["cron", "action"]'
-                          then: '${repository.project}'
-              head_branch:
-                  $if: 'tasks_for == "github-pull-request"'
-                  then: ${event.pull_request.head.ref}
-                  else:
-                      $if: 'tasks_for == "github-push"'
-                      then: ${event.ref}
-                      else:
-                          $if: 'tasks_for in ["action", "cron"]'
-                          then: '${push.branch}'
-              head_sha:
-                  $if: 'tasks_for == "github-push"'
-                  then: '${event.after}'
-                  else:
-                      $if: 'tasks_for == "github-pull-request"'
-                      then: '${event.pull_request.head.sha}'
-                      else:
-                          $if: 'tasks_for in ["action", "cron"]'
-                          then: '${push.revision}'
-
-              ownTaskId:
-                  $if: '"github" in tasks_for'
-                  then: {$eval: as_slugid("decision_task")}
-                  else:
-                      $if: 'tasks_for in ["cron", "action"]'
-                      then: '${ownTaskId}'
-              pullRequestAction:
-                  $if: 'tasks_for == "github-pull-request"'
-                  then: ${event.action}
-                  else: 'UNDEFINED'
-          in:
-              $if: >
-                tasks_for in ["action", "cron"]
-                || (tasks_for == "github-pull-request" && pullRequestAction in ["opened", "reopened", "synchronize"])
-                || (tasks_for == "github-push" && head_branch[:10] != "refs/tags/") && (head_branch != "staging.tmp") && (head_branch != "trying.tmp") && (head_branch[:8] != "mergify/")
-              then:
-                  $let:
-                      level:
-                          $if: 'tasks_for in ["github-push", "action", "cron"] && repoUrl == "https://github.com/mozilla-mobile/fenix"'
-                          then: '3'
-                          else: '1'
-
-                      short_head_branch:
-                          $if: 'head_branch[:11] == "refs/heads/"'
-                          then: {$eval: 'head_branch[11:]'}
-                  in:
-                    $mergeDeep:
-                        - $if: 'tasks_for != "action"'
+        $if: >
+            tasks_for in ["action", "cron"]
+            || (tasks_for == "github-pull-request" && pullRequestAction in ["opened", "reopened", "synchronize"])
+            || (tasks_for == "github-push" && head_branch[:10] != "refs/tags/") && (head_branch != "staging.tmp") && (head_branch != "trying.tmp") && (head_branch[:8] != "mergify/")
+        then:
+            $let:
+                level:
+                    $if: 'tasks_for in ["github-push", "action", "cron"] && repoUrl == "https://github.com/mozilla-mobile/fenix"'
+                    then: '3'
+                    else: '1'
+                short_head_branch:
+                    $if: 'head_branch[:11] == "refs/heads/"'
+                    then: {$eval: 'head_branch[11:]'}
+            in:
+                taskId:
+                    $if: 'tasks_for != "action"'
+                    then: '${ownTaskId}'
+                taskGroupId:
+                    $if: 'tasks_for == "action"'
+                    then: '${action.taskGroupId}'
+                    else: '${ownTaskId}'  # same as taskId; this is how automation identifies a decision task
+                schedulerId: '${trustDomain}-level-${level}'
+                created: {$fromNow: ''}
+                deadline: {$fromNow: '1 day'}
+                expires: {$fromNow: '1 year 1 second'}  # 1 second so artifacts expire first, despite rounding errors
+                metadata:
+                    $merge:
+                        - owner: "${ownerEmail}"
+                          source: '${repoUrl}/raw/${head_sha}/.taskcluster.yml'
+                        - $if: 'tasks_for in ["github-push", "github-pull-request"]'
                           then:
-                              taskId: '${ownTaskId}'
-                        - taskGroupId:
-                              $if: 'tasks_for == "action"'
+                            name: "Decision Task"
+                            description: 'The task that creates all of the other tasks in the task graph'
+                          else:
+                            $if: 'tasks_for == "action"'
+                            then:
+                                name: "Action: ${action.title}"
+                                description: |
+                                    ${action.description}
+
+                                    Action triggered by clientID `${clientId}`
+                            else:
+                                name: "Decision Task for cron job ${cron.job_name}"
+                                description: 'Created by a [cron task](https://firefox-ci-tc.services.mozilla.com/tasks/${cron.task_id})'
+                provisionerId: "${trustDomain}-${level}"
+                workerType: "decision"
+                tags:
+                    $if: 'tasks_for in ["github-push", "github-pull-request"]'
+                    then:
+                        kind: decision-task
+                    else:
+                        $if: 'tasks_for == "action"'
+                        then:
+                            kind: 'action-callback'
+                        else:
+                            $if: 'tasks_for == "cron"'
+                            then:
+                                kind: cron-task
+                routes:
+                    $flattenDeep:
+                        - checks
+                        - $if: 'level == "3" || repoUrl == "https://github.com/mozilla-releng/staging-fenix"'
+                          then:
+                            - tc-treeherder.v2.${project}.${head_sha}
+                            # TODO Bug 1601928: Make this scope fork-friendly once ${project} is better defined. This will enable
+                            # staging release promotion on forks.
+                        - $if: 'tasks_for == "github-push"'
+                          then:
+                            - index.${trustDomain}.v2.${project}.branch.${short_head_branch}.latest.taskgraph.decision
+                            - index.${trustDomain}.v2.${project}.branch.${short_head_branch}.revision.${head_sha}.taskgraph.decision
+                            - index.${trustDomain}.v2.${project}.revision.${head_sha}.taskgraph.decision
+                        - $if: 'tasks_for == "cron"'
+                          then:
+                            # cron context provides ${head_branch} as a short one
+                            - index.${trustDomain}.v2.${project}.branch.${head_branch}.latest.taskgraph.decision-${cron.job_name}
+                            - index.${trustDomain}.v2.${project}.branch.${head_branch}.revision.${head_sha}.taskgraph.decision-${cron.job_name}
+                            - index.${trustDomain}.v2.${project}.branch.${head_branch}.revision.${head_sha}.taskgraph.cron.${ownTaskId}
+                scopes:
+                    $if: 'tasks_for == "github-push"'
+                    then:
+                        # `https://` is 8 characters so, ${repoUrl[8:]} is the repository without the protocol.
+                        - 'assume:repo:${repoUrl[8:]}:branch:${short_head_branch}'
+                    else:
+                        $if: 'tasks_for == "github-pull-request"'
+                        then:
+                            - 'assume:repo:github.com/${event.pull_request.base.repo.full_name}:pull-request'
+                        else:
+                            $if: 'tasks_for == "action"'
+                            then:
+                                # when all actions are hooks, we can calculate this directly rather than using a variable
+                                - '${action.repo_scope}'
+                            else:
+                                - 'assume:repo:${repoUrl[8:]}:cron:${cron.job_name}'
+
+                requires: all-completed
+                priority: lowest
+                retries: 5
+                payload:
+                    env:
+                        # run-task uses these to check out the source; the inputs
+                        # to `mach taskgraph decision` are all on the command line.
+                        $merge:
+                            - MOBILE_BASE_REPOSITORY: '${baseRepoUrl}'
+                              MOBILE_HEAD_REPOSITORY: '${repoUrl}'
+                              MOBILE_HEAD_REF: '${head_branch}'
+                              MOBILE_HEAD_REV: '${head_sha}'
+                              MOBILE_REPOSITORY_TYPE: git
+                              MOBILE_PIP_REQUIREMENTS: taskcluster/requirements.txt
+                              REPOSITORIES: {$json: {mobile: "Fenix"}}
+                              HG_STORE_PATH: /builds/worker/checkouts/hg-store
+                              ANDROID_SDK_ROOT: /builds/worker/android-sdk
+                            - $if: 'tasks_for in ["github-pull-request"]'
                               then:
-                                  '${action.taskGroupId}'
-                              else:
-                                  '${ownTaskId}'  # same as taskId; this is how automation identifies a decision task
-                          schedulerId: '${trustDomain}-level-${level}'
-                          created: {$fromNow: ''}
-                          deadline: {$fromNow: '1 day'}
-                          expires: {$fromNow: '1 year 1 second'}  # 1 second so artifacts expire first, despite rounding errors
-                          metadata:
-                              $merge:
-                                  - owner: "${ownerEmail}"
-                                    source: '${repoUrl}/raw/${head_sha}/.taskcluster.yml'
-                                  - $if: 'tasks_for in ["github-push", "github-pull-request"]'
+                                MOBILE_PULL_REQUEST_NUMBER: '${event.pull_request.number}'
+                            - $if: 'tasks_for == "action"'
+                              then:
+                                ACTION_TASK_GROUP_ID: '${action.taskGroupId}'  # taskGroupId of the target task
+                                ACTION_TASK_ID: {$json: {$eval: 'taskId'}}  # taskId of the target task (JSON-encoded)
+                                ACTION_INPUT: {$json: {$eval: 'input'}}
+                                ACTION_CALLBACK: '${action.cb_name}'
+                    features:
+                        taskclusterProxy: true
+                        chainOfTrust: true
+                        # Note: This task is built server side without the context or tooling that
+                        # exist in tree so we must hard code the hash
+                    image: mozillareleases/taskgraph:decision-mobile-7e11b0cc3966ad9729e08b19551399b3343d3b385eac067b6335d4c34431a899@sha256:b309fa59efd59991ba286a326cb43b724c38e6f3872c52d0f85e96428899c2fc
+
+                    maxRunTime: 1800
+
+                    command:
+                        - /usr/local/bin/run-task
+                        - '--mobile-checkout=/builds/worker/checkouts/src'
+                        - '--task-cwd=/builds/worker/checkouts/src'
+                        - '--'
+                        - bash
+                        - -cx
+                        - $let:
+                            extraArgs: 
+                                $if: 'tasks_for == "cron"'
+                                then: '${cron.quoted_args}'
+                                else: ''
+                          in:
+                            $if: 'tasks_for == "action"'
+                            then: >
+                                taskcluster/scripts/decision-install-sdk.sh &&
+                                ln -s /builds/worker/artifacts artifacts &&
+                                ~/.local/bin/taskgraph action-callback
+                            else: >
+                                taskcluster/scripts/decision-install-sdk.sh &&
+                                ln -s /builds/worker/artifacts artifacts &&
+                                ~/.local/bin/taskgraph decision
+                                --pushlog-id='0'
+                                --pushdate='0'
+                                --project='${project}'
+                                --message=""
+                                --owner='${ownerEmail}'
+                                --level='${level}'
+                                --base-repository="$MOBILE_BASE_REPOSITORY"
+                                --head-repository="$MOBILE_HEAD_REPOSITORY"
+                                --head-ref="$MOBILE_HEAD_REF"
+                                --head-rev="$MOBILE_HEAD_REV"
+                                --repository-type="$MOBILE_REPOSITORY_TYPE"
+                                --tasks-for='${tasks_for}'
+                                ${extraArgs}
+
+                    artifacts:
+                        'public':
+                            type: 'directory'
+                            path: '/builds/worker/artifacts'
+                            expires: 
+                                $fromNow: '1 year'
+                        'public/docker-contexts':
+                            type: 'directory'
+                            path: '/builds/worker/checkouts/src/docker-contexts'
+                            # This needs to be at least the deadline of the
+                            # decision task + the docker-image task deadlines.
+                            # It is set to a week to allow for some time for
+                            # debugging, but they are not useful long-term.
+                            expires: 
+                                $fromNow: '7 day'
+
+                extra:
+                    $merge:
+                        - treeherder:
+                            $merge:
+                                - machine:
+                                    platform: gecko-decision
+                                - $if: 'tasks_for in ["github-push", "github-pull-request"]'
+                                  then:
+                                    symbol: D
+                                  else:
+                                    $if: 'tasks_for == "action"'
                                     then:
-                                        name: "Decision Task"
-                                        description: 'The task that creates all of the other tasks in the task graph'
+                                        groupName: 'action-callback'
+                                        groupSymbol: AC
+                                        symbol: "${action.symbol}"
                                     else:
-                                        $if: 'tasks_for == "action"'
-                                        then:
-                                            name: "Action: ${action.title}"
-                                            description: |
-                                                ${action.description}
-
-                                                Action triggered by clientID `${clientId}`
-                                        else:
-                                            name: "Decision Task for cron job ${cron.job_name}"
-                                            description: 'Created by a [cron task](https://firefox-ci-tc.services.mozilla.com/tasks/${cron.task_id})'
-                          provisionerId: "mobile-${level}"
-                          workerType: "decision"
-                          tags:
-                              $if: 'tasks_for in ["github-push", "github-pull-request"]'
-                              then:
-                                  kind: decision-task
-                              else:
-                                  $if: 'tasks_for == "action"'
-                                  then:
-                                      kind: 'action-callback'
-                                  else:
-                                      $if: 'tasks_for == "cron"'
-                                      then:
-                                          kind: cron-task
-                          routes:
-                              $flattenDeep:
-                                  - checks
-                                  - $if: 'level == "3" || repoUrl == "https://github.com/mozilla-releng/staging-fenix"'
-                                    then:
-                                        - tc-treeherder.v2.${project}.${head_sha}
-                                        # TODO Bug 1601928: Make this scope fork-friendly once ${project} is better defined. This will enable
-                                        # staging release promotion on forks.
-                                        - $if: 'tasks_for == "github-push"'
-                                          then:
-                                              - index.mobile.v2.${project}.branch.${short_head_branch}.latest.taskgraph.decision
-                                              - index.mobile.v2.${project}.branch.${short_head_branch}.revision.${head_sha}.taskgraph.decision
-                                              - index.mobile.v2.${project}.revision.${head_sha}.taskgraph.decision
-                                        - $if: 'tasks_for == "cron"'
-                                          then:
-                                              # cron context provides ${head_branch} as a short one
-                                              - index.mobile.v2.${project}.branch.${head_branch}.latest.taskgraph.decision-${cron.job_name}
-                                              - index.mobile.v2.${project}.branch.${head_branch}.revision.${head_sha}.taskgraph.decision-${cron.job_name}
-                                              - index.mobile.v2.${project}.branch.${head_branch}.revision.${head_sha}.taskgraph.cron.${ownTaskId}
-                          scopes:
-                              $if: 'tasks_for == "github-push"'
-                              then:
-                                  # `https://` is 8 characters so, ${repoUrl[8:]} is the repository without the protocol.
-                                  - 'assume:repo:${repoUrl[8:]}:branch:${short_head_branch}'
-                              else:
-                                  $if: 'tasks_for == "github-pull-request"'
-                                  then:
-                                      - 'assume:repo:github.com/${event.pull_request.base.repo.full_name}:pull-request'
-                                  else:
-                                      $if: 'tasks_for == "action"'
-                                      then:
-                                          # when all actions are hooks, we can calculate this directly rather than using a variable
-                                          - '${action.repo_scope}'
-                                      else:
-                                          - 'assume:repo:${repoUrl[8:]}:cron:${cron.job_name}'
-
-                          requires: all-completed
-                          priority: lowest
-                          retries: 5
-
-                          payload:
-                              env:
-                                  # run-task uses these to check out the source; the inputs
-                                  # to `mach taskgraph decision` are all on the command line.
-                                  $merge:
-                                      - MOBILE_BASE_REPOSITORY: '${baseRepoUrl}'
-                                        MOBILE_HEAD_REPOSITORY: '${repoUrl}'
-                                        MOBILE_HEAD_REF: '${head_branch}'
-                                        MOBILE_HEAD_REV: '${head_sha}'
-                                        MOBILE_REPOSITORY_TYPE: git
-                                        TASKGRAPH_BASE_REPOSITORY: https://hg.mozilla.org/ci/taskgraph
-                                        TASKGRAPH_HEAD_REPOSITORY: https://hg.mozilla.org/ci/${taskgraph.branch}
-                                        TASKGRAPH_HEAD_REV: ${taskgraph.revision}
-                                        TASKGRAPH_REPOSITORY_TYPE: hg
-                                        REPOSITORIES: {$json: {mobile: "Fenix", taskgraph: "Taskgraph"}}
-                                        HG_STORE_PATH: /builds/worker/checkouts/hg-store
-                                        ANDROID_SDK_ROOT: /builds/worker/android-sdk
-                                      - $if: 'tasks_for in ["github-pull-request"]'
-                                        then:
-                                            MOBILE_PULL_REQUEST_NUMBER: '${event.pull_request.number}'
-                                      - $if: 'tasks_for == "action"'
-                                        then:
-                                            ACTION_TASK_GROUP_ID: '${action.taskGroupId}'  # taskGroupId of the target task
-                                            ACTION_TASK_ID: {$json: {$eval: 'taskId'}}  # taskId of the target task (JSON-encoded)
-                                            ACTION_INPUT: {$json: {$eval: 'input'}}
-                                            ACTION_CALLBACK: '${action.cb_name}'
-                              features:
-                                  taskclusterProxy: true
-                                  chainOfTrust: true
-                              # Note: This task is built server side without the context or tooling that
-                              # exist in tree so we must hard code the hash
-                              image:
-                                  mozillareleases/taskgraph:decision-mobile-44b6b7b4c370220eff56efa8b508aa5157ef9c6e74847c7ecc19d640946ba49e@sha256:4107cbc5e154502529e4d38efa4dc89c05ee54e2cbc6e2e66023e68407502894
-
-                              maxRunTime: 1800
-
-                              command:
-                                  - /usr/local/bin/run-task
-                                  - '--mobile-checkout=/builds/worker/checkouts/vcs'
-                                  - '--taskgraph-checkout=/builds/worker/checkouts/taskgraph'
-                                  - '--task-cwd=/builds/worker/checkouts/vcs'
-                                  - '--'
-                                  - bash
-                                  - -cx
-                                  - $let:
-                                        extraArgs: {$if: 'tasks_for == "cron"', then: '${cron.quoted_args}', else: ''}
-                                    in:
-                                        $if: 'tasks_for == "action"'
-                                        then: >
-                                            PIP_IGNORE_INSTALLED=0 pip3 install --user /builds/worker/checkouts/taskgraph &&
-                                            PIP_IGNORE_INSTALLED=0 pip3 install --user mozilla-version &&
-                                            taskcluster/scripts/decision-install-sdk.sh &&
-                                            ln -s /builds/worker/artifacts artifacts &&
-                                            ~/.local/bin/taskgraph action-callback
-                                        else: >
-                                            PIP_IGNORE_INSTALLED=0 pip3 install --user /builds/worker/checkouts/taskgraph &&
-                                            PIP_IGNORE_INSTALLED=0 pip3 install --user mozilla-version &&
-                                            taskcluster/scripts/decision-install-sdk.sh &&
-                                            ln -s /builds/worker/artifacts artifacts &&
-                                            ~/.local/bin/taskgraph decision
-                                            --pushlog-id='0'
-                                            --pushdate='0'
-                                            --project='${project}'
-                                            --message=""
-                                            --owner='${ownerEmail}'
-                                            --level='${level}'
-                                            --base-repository="$MOBILE_BASE_REPOSITORY"
-                                            --head-repository="$MOBILE_HEAD_REPOSITORY"
-                                            --head-ref="$MOBILE_HEAD_REF"
-                                            --head-rev="$MOBILE_HEAD_REV"
-                                            --repository-type="$MOBILE_REPOSITORY_TYPE"
-                                            --tasks-for='${tasks_for}'
-                                            ${extraArgs}
-
-                              artifacts:
-                                  'public':
-                                      type: 'directory'
-                                      path: '/builds/worker/artifacts'
-                                      expires: {$fromNow: '1 year'}
-                                  'public/docker-contexts':
-                                      type: 'directory'
-                                      path: '/builds/worker/checkouts/vcs/docker-contexts'
-                                      # This needs to be at least the deadline of the
-                                      # decision task + the docker-image task deadlines.
-                                      # It is set to a week to allow for some time for
-                                      # debugging, but they are not useful long-term.
-                                      expires: {$fromNow: '7 day'}
-
-                          extra:
-                              $merge:
-                                  - treeherder:
-                                        $merge:
-                                            - machine:
-                                                  platform: gecko-decision
-                                            - $if: 'tasks_for in ["github-push", "github-pull-request"]'
-                                              then:
-                                                  symbol: D
-                                              else:
-                                                  $if: 'tasks_for == "action"'
-                                                  then:
-                                                      groupName: 'action-callback'
-                                                      groupSymbol: AC
-                                                      symbol: "${action.symbol}"
-                                                  else:
-                                                      groupSymbol: cron
-                                                      symbol: "${cron.job_symbol}"
-                                  - $if: 'tasks_for == "action"'
-                                    then:
-                                        parent: '${action.taskGroupId}'
-                                        action:
-                                            name: '${action.name}'
-                                            context:
-                                                taskGroupId: '${action.taskGroupId}'
-                                                taskId: {$eval: 'taskId'}
-                                                input: {$eval: 'input'}
-                                                clientId: {$eval: 'clientId'}
-                                  - $if: 'tasks_for == "cron"'
-                                    then:
-                                        cron: {$json: {$eval: 'cron'}}
-                                  - tasks_for: '${tasks_for}'
+                                        groupSymbol: cron
+                                        symbol: "${cron.job_symbol}"
+                        - $if: 'tasks_for == "action"'
+                          then:
+                            parent: '${action.taskGroupId}'
+                            action:
+                                name: '${action.name}'
+                                context:
+                                    taskGroupId: '${action.taskGroupId}'
+                                    taskId: {$eval: 'taskId'}
+                                    input: {$eval: 'input'}
+                                    clientId: {$eval: 'clientId'}
+                        - $if: 'tasks_for == "cron"'
+                          then:
+                            cron: {$json: {$eval: 'cron'}}
+                        - tasks_for: '${tasks_for}'
diff --git a/taskcluster/fenix_taskgraph/__init__.py b/taskcluster/fenix_taskgraph/__init__.py
index 37cd6ff80b..2e46544c50 100644
--- a/taskcluster/fenix_taskgraph/__init__.py
+++ b/taskcluster/fenix_taskgraph/__init__.py
@@ -2,8 +2,6 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from importlib import import_module
 
 
@@ -12,14 +10,16 @@ def register(graph_config):
     Import all modules that are siblings of this one, triggering decorators in
     the process.
     """
-    _import_modules([
-        "job",
-        "parameters",
-        "release_promotion",
-        "routes",
-        "target_tasks",
-        "worker_types",
-    ])
+    _import_modules(
+        [
+            "job",
+            "parameters",
+            "release_promotion",
+            "routes",
+            "target_tasks",
+            "worker_types",
+        ]
+    )
 
 
 def _import_modules(modules):
diff --git a/taskcluster/fenix_taskgraph/gradle.py b/taskcluster/fenix_taskgraph/gradle.py
index 119048fef0..76b72e45fa 100644
--- a/taskcluster/fenix_taskgraph/gradle.py
+++ b/taskcluster/fenix_taskgraph/gradle.py
@@ -2,48 +2,48 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 import json
 import subprocess
 
 from taskgraph.util.memoize import memoize
 
 
-
 def get_variant(build_type):
     all_variants = _fetch_all_variants()
     matching_variants = [
-        variant for variant in all_variants
-        if variant["build_type"] == build_type
+        variant for variant in all_variants if variant["build_type"] == build_type
     ]
     number_of_matching_variants = len(matching_variants)
     if number_of_matching_variants == 0:
-        raise ValueError('No variant found for build type "{}"'.format(
-            build_type
-        ))
+        raise ValueError('No variant found for build type "{}"'.format(build_type))
     elif number_of_matching_variants > 1:
-        raise ValueError('Too many variants found for build type "{}"": {}'.format(
-            build_type, matching_variants
-        ))
+        raise ValueError(
+            'Too many variants found for build type "{}"": {}'.format(
+                build_type, matching_variants
+            )
+        )
 
     return matching_variants.pop()
 
 
 @memoize
 def _fetch_all_variants():
-    output = _run_gradle_process('printVariants')
-    content = _extract_content_from_command_output(output, prefix='variants: ')
+    output = _run_gradle_process("printVariants")
+    content = _extract_content_from_command_output(output, prefix="variants: ")
     return json.loads(content)
 
 
 def _run_gradle_process(gradle_command, **kwargs):
     gradle_properties = [
-        '-P{property_name}={value}'.format(property_name=property_name, value=value)
+        "-P{property_name}={value}".format(property_name=property_name, value=value)
         for property_name, value in kwargs.items()
     ]
 
-    process = subprocess.Popen(["./gradlew", "--no-daemon", "--quiet", gradle_command] + gradle_properties, stdout=subprocess.PIPE, universal_newlines=True)
+    process = subprocess.Popen(
+        ["./gradlew", "--no-daemon", "--quiet", gradle_command] + gradle_properties,
+        stdout=subprocess.PIPE,
+        universal_newlines=True,
+    )
     output, err = process.communicate()
     exit_code = process.wait()
 
@@ -54,5 +54,5 @@ def _run_gradle_process(gradle_command, **kwargs):
 
 
 def _extract_content_from_command_output(output, prefix):
-    variants_line = [line for line in output.split('\n') if line.startswith(prefix)][0]
-    return variants_line.split(' ', 1)[1]
+    variants_line = [line for line in output.split("\n") if line.startswith(prefix)][0]
+    return variants_line.split(" ", 1)[1]
diff --git a/taskcluster/fenix_taskgraph/job.py b/taskcluster/fenix_taskgraph/job.py
index 0f33ec5e4e..df31f6a325 100644
--- a/taskcluster/fenix_taskgraph/job.py
+++ b/taskcluster/fenix_taskgraph/job.py
@@ -2,50 +2,51 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.job import run_job_using, configure_taskdesc_for_run
 from taskgraph.util import path
 from taskgraph.util.schema import Schema, taskref_or_string
 from voluptuous import Required, Optional
-from six import text_type
 
 from pipes import quote as shell_quote
 
 secret_schema = {
-    Required("name"): text_type,
-    Required("path"): text_type,
-    Required("key"): text_type,
+    Required("name"): str,
+    Required("path"): str,
+    Required("key"): str,
     Optional("json"): bool,
 }
 
 dummy_secret_schema = {
-    Required("content"): text_type,
-    Required("path"): text_type,
+    Required("content"): str,
+    Required("path"): str,
     Optional("json"): bool,
 }
 
-gradlew_schema = Schema({
-    Required("using"): "gradlew",
-    Optional("pre-gradlew"): [[text_type]],
-    Required("gradlew"): [text_type],
-    Optional("post-gradlew"): [[text_type]],
-    # Base work directory used to set up the task.
-    Required("workdir"): text_type,
-    Optional("use-caches"): bool,
-    Optional("secrets"): [secret_schema],
-    Optional("dummy-secrets"): [dummy_secret_schema],
-})
+gradlew_schema = Schema(
+    {
+        Required("using"): "gradlew",
+        Optional("pre-gradlew"): [[str]],
+        Required("gradlew"): [str],
+        Optional("post-gradlew"): [[str]],
+        # Base work directory used to set up the task.
+        Required("workdir"): str,
+        Optional("use-caches"): bool,
+        Optional("secrets"): [secret_schema],
+        Optional("dummy-secrets"): [dummy_secret_schema],
+    }
+)
 
-run_commands_schema = Schema({
-    Required("using"): "run-commands",
-    Optional("pre-commands"): [[text_type]],
-    Required("commands"): [[taskref_or_string]],
-    Required("workdir"): text_type,
-    Optional("use-caches"): bool,
-    Optional("secrets"): [secret_schema],
-    Optional("dummy-secrets"): [dummy_secret_schema],
-})
+run_commands_schema = Schema(
+    {
+        Required("using"): "run-commands",
+        Optional("pre-commands"): [[str]],
+        Required("commands"): [[taskref_or_string]],
+        Required("workdir"): str,
+        Optional("use-caches"): bool,
+        Optional("secrets"): [secret_schema],
+        Optional("dummy-secrets"): [dummy_secret_schema],
+    }
+)
 
 
 @run_job_using("docker-worker", "run-commands", schema=run_commands_schema)
@@ -53,7 +54,8 @@ def configure_run_commands_schema(config, job, taskdesc):
     run = job["run"]
     pre_commands = run.pop("pre-commands", [])
     pre_commands += [
-        _generate_dummy_secret_command(secret) for secret in run.pop("dummy-secrets", [])
+        _generate_dummy_secret_command(secret)
+        for secret in run.pop("dummy-secrets", [])
     ]
     pre_commands += [
         _generate_secret_command(secret) for secret in run.get("secrets", [])
@@ -73,11 +75,9 @@ def configure_gradlew(config, job, taskdesc):
     worker = taskdesc["worker"] = job["worker"]
 
     fetches_dir = path.join(run["workdir"], worker["env"]["MOZ_FETCHES_DIR"])
-    worker.setdefault("env", {}).update({
-        "ANDROID_SDK_ROOT": path.join(
-            fetches_dir, "android-sdk-linux"
-        )
-    })
+    worker.setdefault("env", {}).update(
+        {"ANDROID_SDK_ROOT": path.join(fetches_dir, "android-sdk-linux")}
+    )
 
     run["command"] = _extract_gradlew_command(run, fetches_dir)
     _inject_secrets_scopes(run, taskdesc)
@@ -88,7 +88,8 @@ def configure_gradlew(config, job, taskdesc):
 def _extract_gradlew_command(run, fetches_dir):
     pre_gradle_commands = run.pop("pre-gradlew", [])
     pre_gradle_commands += [
-        _generate_dummy_secret_command(secret) for secret in run.pop("dummy-secrets", [])
+        _generate_dummy_secret_command(secret)
+        for secret in run.pop("dummy-secrets", [])
     ]
     pre_gradle_commands += [
         _generate_secret_command(secret) for secret in run.get("secrets", [])
@@ -101,7 +102,9 @@ def _extract_gradlew_command(run, fetches_dir):
         )
         for repo_name in ("google", "central")
     ]
-    gradle_command = ["./gradlew"] + gradle_repos_args + ["listRepositories"] + run.pop("gradlew")
+    gradle_command = (
+        ["./gradlew"] + gradle_repos_args + ["listRepositories"] + run.pop("gradlew")
+    )
     post_gradle_commands = run.pop("post-gradlew", [])
 
     commands = pre_gradle_commands + [gradle_command] + post_gradle_commands
@@ -111,9 +114,12 @@ def _extract_gradlew_command(run, fetches_dir):
 def _generate_secret_command(secret):
     secret_command = [
         "taskcluster/scripts/get-secret.py",
-        "-s", secret["name"],
-        "-k", secret["key"],
-        "-f", secret["path"],
+        "-s",
+        secret["name"],
+        "-k",
+        secret["key"],
+        "-f",
+        secret["path"],
     ]
     if secret.get("json"):
         secret_command.append("--json")
@@ -124,8 +130,10 @@ def _generate_secret_command(secret):
 def _generate_dummy_secret_command(secret):
     secret_command = [
         "taskcluster/scripts/write-dummy-secret.py",
-        "-f", secret["path"],
-        "-c", secret["content"],
+        "-f",
+        secret["path"],
+        "-c",
+        secret["content"],
     ]
     if secret.get("json"):
         secret_command.append("--json")
@@ -149,18 +157,22 @@ def _convert_commands_to_string(commands):
                     part_string = part["task-reference"]
                     should_task_reference = True
                 else:
-                    raise ValueError('Unsupported dict: {}'.format(part))
+                    raise ValueError("Unsupported dict: {}".format(part))
             else:
                 part_string = part
 
             sanitized_parts.append(part_string)
         sanitized_commands.append(sanitized_parts)
 
-    shell_quoted_commands = [" ".join(map(shell_quote, command)) for command in sanitized_commands]
+    shell_quoted_commands = [
+        " ".join(map(shell_quote, command)) for command in sanitized_commands
+    ]
     full_string_command = " && ".join(shell_quoted_commands)
 
     if should_artifact_reference and should_task_reference:
-        raise NotImplementedError('"arifact-reference" and "task-reference" cannot be both used')
+        raise NotImplementedError(
+            '"arifact-reference" and "task-reference" cannot be both used'
+        )
     elif should_artifact_reference:
         return {"artifact-reference": full_string_command}
     elif should_task_reference:
@@ -173,7 +185,9 @@ def _inject_secrets_scopes(run, taskdesc):
     secrets = run.pop("secrets", [])
     scopes = taskdesc.setdefault("scopes", [])
     new_secret_scopes = ["secrets:get:{}".format(secret["name"]) for secret in secrets]
-    new_secret_scopes = list(set(new_secret_scopes))  # Scopes must not have any duplicates
+    new_secret_scopes = list(
+        set(new_secret_scopes)
+    )  # Scopes must not have any duplicates
     scopes.extend(new_secret_scopes)
 
 
diff --git a/taskcluster/fenix_taskgraph/loader/__init__.py b/taskcluster/fenix_taskgraph/loader/__init__.py
index aa76d6676d..c07732f691 100644
--- a/taskcluster/fenix_taskgraph/loader/__init__.py
+++ b/taskcluster/fenix_taskgraph/loader/__init__.py
@@ -2,8 +2,6 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 import copy
 
 
@@ -15,12 +13,12 @@ def group_by(name):
     def wrapper(func):
         GROUP_BY_MAP[name] = func
         return func
+
     return wrapper
 
 
-
 def group_tasks(config, tasks):
-    group_by_fn = GROUP_BY_MAP[config['group-by']]
+    group_by_fn = GROUP_BY_MAP[config["group-by"]]
 
     groups = group_by_fn(config, tasks)
 
@@ -29,33 +27,33 @@ def group_tasks(config, tasks):
         yield dependencies
 
 
-@group_by('build-type')
+@group_by("build-type")
 def build_type_grouping(config, tasks):
     groups = {}
-    kind_dependencies = config.get('kind-dependencies')
-    only_build_type = config.get('only-for-build-types')
+    kind_dependencies = config.get("kind-dependencies")
+    only_build_type = config.get("only-for-build-types")
 
     for task in tasks:
         if task.kind not in kind_dependencies:
             continue
 
         if only_build_type:
-            build_type = task.attributes.get('build-type')
+            build_type = task.attributes.get("build-type")
             if build_type not in only_build_type:
                 continue
 
-        build_type = task.attributes.get('build-type')
+        build_type = task.attributes.get("build-type")
 
         groups.setdefault(build_type, []).append(task)
 
     return groups
 
 
-@group_by('attributes')
+@group_by("attributes")
 def attributes_grouping(config, tasks):
     groups = {}
-    kind_dependencies = config.get('kind-dependencies')
-    only_attributes = config.get('only-for-attributes')
+    kind_dependencies = config.get("kind-dependencies")
+    only_attributes = config.get("only-for-attributes")
 
     for task in tasks:
         if task.kind not in kind_dependencies:
diff --git a/taskcluster/fenix_taskgraph/loader/multi_dep.py b/taskcluster/fenix_taskgraph/loader/multi_dep.py
index 8f527c7941..3309f85bf8 100644
--- a/taskcluster/fenix_taskgraph/loader/multi_dep.py
+++ b/taskcluster/fenix_taskgraph/loader/multi_dep.py
@@ -2,27 +2,25 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 import copy
 
 from voluptuous import Required
 
 from taskgraph.task import Task
-from taskgraph.util.attributes import sorted_unique_list
 from taskgraph.util.schema import Schema
 
 from . import group_tasks
 
 
-schema = Schema({
-    Required('primary-dependency', 'primary dependency task'): Task,
-    Required(
-        'dependent-tasks',
-        'dictionary of dependent tasks, keyed by kind',
-    ): {str: Task},
-})
-
+schema = Schema(
+    {
+        Required("primary-dependency", "primary dependency task"): Task,
+        Required(
+            "dependent-tasks",
+            "dictionary of dependent tasks, keyed by kind",
+        ): {str: Task},
+    }
+)
 
 
 def loader(kind, path, config, params, loaded_tasks):
@@ -39,7 +37,7 @@ def loader(kind, path, config, params, loaded_tasks):
     Optional ``job-template`` kind configuration value, if specified, will be used to
     pass configuration down to the specified transforms used.
     """
-    job_template = config.get('job-template')
+    job_template = config.get("job-template")
 
     for dep_tasks in group_tasks(config, loaded_tasks):
         kinds = [dep.kind for dep in dep_tasks]
@@ -50,8 +48,8 @@ def loader(kind, path, config, params, loaded_tasks):
             for dep in dep_tasks
         }
 
-        job = {'dependent-tasks': dep_tasks_per_unique_key}
-        job['primary-dependency'] = get_primary_dep(config, dep_tasks_per_unique_key)
+        job = {"dependent-tasks": dep_tasks_per_unique_key}
+        job["primary-dependency"] = get_primary_dep(config, dep_tasks_per_unique_key)
         if job_template:
             job.update(copy.deepcopy(job_template))
 
@@ -65,7 +63,7 @@ def get_primary_dep(config, dep_tasks):
     defined and is a list, the first kind in that list with a matching dep
     is the primary dependency. If it's undefined, return the first dep.
     """
-    primary_dependencies = config.get('primary-dependency')
+    primary_dependencies = config.get("primary-dependency")
     if isinstance(primary_dependencies, str):
         primary_dependencies = [primary_dependencies]
     if not primary_dependencies:
@@ -75,13 +73,16 @@ def get_primary_dep(config, dep_tasks):
     for primary_kind in primary_dependencies:
         for dep_kind in dep_tasks:
             if dep_kind == primary_kind:
-                assert primary_dep is None, \
-                    "Too many primary dependent tasks in dep_tasks: {}!".format(
-                        [t.label for t in dep_tasks]
-                    )
+                assert (
+                    primary_dep is None
+                ), "Too many primary dependent tasks in dep_tasks: {}!".format(
+                    [t.label for t in dep_tasks]
+                )
                 primary_dep = dep_tasks[dep_kind]
     if primary_dep is None:
-        raise Exception("Can't find dependency of {}: {}".format(
-            config['primary-dependency'], config
-        ))
+        raise Exception(
+            "Can't find dependency of {}: {}".format(
+                config["primary-dependency"], config
+            )
+        )
     return primary_dep
diff --git a/taskcluster/fenix_taskgraph/parameters.py b/taskcluster/fenix_taskgraph/parameters.py
index 9561cde5bf..937461e114 100644
--- a/taskcluster/fenix_taskgraph/parameters.py
+++ b/taskcluster/fenix_taskgraph/parameters.py
@@ -2,36 +2,21 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 import os
-import re
 
-from mozilla_version.fenix import FenixVersion
-from six import text_type
 from taskgraph.parameters import extend_parameters_schema
 from voluptuous import All, Any, Optional, Range, Required
 
-from .release_promotion import read_version_file
 
-
-def get_defaults(repo_root):
-    return {
-        "pull_request_number": None,
-        "release_type": "",
-        "shipping_phase": None,
-        "next_version": "",
-        "version": "",
+extend_parameters_schema(
+    {
+        Required("pull_request_number"): Any(All(int, Range(min=1)), None),
+        Required("release_type", default=""): str,
+        Optional("shipping_phase"): Any("build", "ship", None),
+        Required("version", default=""): str,
+        Required("next_version", default=""): Any(None, str),
     }
-
-
-extend_parameters_schema({
-    Required("pull_request_number"): Any(All(int, Range(min=1)), None),
-    Required("release_type"): text_type,
-    Optional("shipping_phase"): Any('build', 'ship', None),
-    Required("version"): text_type,
-    Required("next_version"): Any(None, text_type),
-}, defaults_fn=get_defaults)
+)
 
 
 def get_decision_parameters(graph_config, parameters):
diff --git a/taskcluster/fenix_taskgraph/release_promotion.py b/taskcluster/fenix_taskgraph/release_promotion.py
index c75a69b7cf..c9c9cf5bba 100644
--- a/taskcluster/fenix_taskgraph/release_promotion.py
+++ b/taskcluster/fenix_taskgraph/release_promotion.py
@@ -2,8 +2,6 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 import os
 
 from mozilla_version.fenix import FenixVersion
@@ -13,7 +11,10 @@ from taskgraph.util.taskcluster import get_artifact
 from taskgraph.taskgraph import TaskGraph
 from taskgraph.decision import taskgraph_decision
 from taskgraph.parameters import Parameters
-from taskgraph.util.taskgraph import find_decision_task, find_existing_tasks_from_previous_kinds
+from taskgraph.util.taskgraph import (
+    find_decision_task,
+    find_existing_tasks_from_previous_kinds,
+)
 
 RELEASE_PROMOTION_PROJECTS = (
     "https://github.com/mozilla-mobile/fenix",
@@ -22,74 +23,84 @@ RELEASE_PROMOTION_PROJECTS = (
 
 
 def is_release_promotion_available(parameters):
-    return parameters['head_repository'] in RELEASE_PROMOTION_PROJECTS
+    return parameters["head_repository"] in RELEASE_PROMOTION_PROJECTS
 
 
 @register_callback_action(
-    name='release-promotion',
-    title='Ship Fenix',
-    symbol='${input.release_promotion_flavor}',
+    name="release-promotion",
+    title="Ship Fenix",
+    symbol="${input.release_promotion_flavor}",
     description="Ship Fenix",
     generic=False,
     order=500,
     context=[],
     available=is_release_promotion_available,
     schema=lambda graph_config: {
-        'type': 'object',
-        'properties': {
-            'build_number': {
-                'type': 'integer',
-                'default': 1,
-                'minimum': 1,
-                'title': 'The release build number',
-                'description': ('The release build number. Starts at 1 per '
-                                'release version, and increments on rebuild.'),
+        "type": "object",
+        "properties": {
+            "build_number": {
+                "type": "integer",
+                "default": 1,
+                "minimum": 1,
+                "title": "The release build number",
+                "description": (
+                    "The release build number. Starts at 1 per "
+                    "release version, and increments on rebuild."
+                ),
             },
-            'do_not_optimize': {
-                'type': 'array',
-                'description': ('Optional: a list of labels to avoid optimizing out '
-                                'of the graph (to force a rerun of, say, '
-                                'funsize docker-image tasks).'),
-                'items': {
-                    'type': 'string',
+            "do_not_optimize": {
+                "type": "array",
+                "description": (
+                    "Optional: a list of labels to avoid optimizing out "
+                    "of the graph (to force a rerun of, say, "
+                    "funsize docker-image tasks)."
+                ),
+                "items": {
+                    "type": "string",
                 },
             },
-            'revision': {
-                'type': 'string',
-                'title': 'Optional: revision to ship',
-                'description': ('Optional: the revision to ship.'),
+            "revision": {
+                "type": "string",
+                "title": "Optional: revision to ship",
+                "description": ("Optional: the revision to ship."),
             },
-            'release_promotion_flavor': {
-                'type': 'string',
-                'description': 'The flavor of release promotion to perform.',
-                'default': 'build',
-                'enum': sorted(graph_config['release-promotion']['flavors'].keys()),
+            "release_promotion_flavor": {
+                "type": "string",
+                "description": "The flavor of release promotion to perform.",
+                "default": "build",
+                "enum": sorted(graph_config["release-promotion"]["flavors"].keys()),
             },
-            'rebuild_kinds': {
-                'type': 'array',
-                'description': ('Optional: an array of kinds to ignore from the previous '
-                                'graph(s).'),
-                'items': {
-                    'type': 'string',
+            "rebuild_kinds": {
+                "type": "array",
+                "description": (
+                    "Optional: an array of kinds to ignore from the previous "
+                    "graph(s)."
+                ),
+                "items": {
+                    "type": "string",
                 },
             },
-            'previous_graph_ids': {
-                'type': 'array',
-                'description': ('Optional: an array of taskIds of decision or action '
-                                'tasks from the previous graph(s) to use to populate '
-                                'our `previous_graph_kinds`.'),
-                'items': {
-                    'type': 'string',
+            "previous_graph_ids": {
+                "type": "array",
+                "description": (
+                    "Optional: an array of taskIds of decision or action "
+                    "tasks from the previous graph(s) to use to populate "
+                    "our `previous_graph_kinds`."
+                ),
+                "items": {
+                    "type": "string",
                 },
             },
-            'version': {
-                'type': 'string',
-                'description': ('Optional: override the version for release promotion. '
-                                "Occasionally we'll land a taskgraph fix in a later "
-                                'commit, but want to act on a build from a previous '
-                                'commit. If a version bump has landed in the meantime, '
-                                'relying on the in-tree version will break things.'),
-                'default': '',
+            "version": {
+                "type": "string",
+                "description": (
+                    "Optional: override the version for release promotion. "
+                    "Occasionally we'll land a taskgraph fix in a later "
+                    "commit, but want to act on a build from a previous "
+                    "commit. If a version bump has landed in the meantime, "
+                    "relying on the in-tree version will break things."
+                ),
+                "default": "",
             },
             "next_version": {
                 "type": "string",
@@ -97,23 +108,34 @@ def is_release_promotion_available(parameters):
                 "default": "",
             },
         },
-        "required": ["release_promotion_flavor", "version", "build_number", "next_version"],
-    }
+        "required": [
+            "release_promotion_flavor",
+            "version",
+            "build_number",
+            "next_version",
+        ],
+    },
 )
 def release_promotion_action(parameters, graph_config, input, task_group_id, task_id):
-    release_promotion_flavor = input['release_promotion_flavor']
-    promotion_config = graph_config['release-promotion']['flavors'][release_promotion_flavor]
+    release_promotion_flavor = input["release_promotion_flavor"]
+    promotion_config = graph_config["release-promotion"]["flavors"][
+        release_promotion_flavor
+    ]
 
-    target_tasks_method = promotion_config['target-tasks-method'].format(
-        project=parameters['project']
+    target_tasks_method = promotion_config["target-tasks-method"].format(
+        project=parameters["project"]
+    )
+    rebuild_kinds = input.get("rebuild_kinds") or promotion_config.get(
+        "rebuild-kinds", []
+    )
+    do_not_optimize = input.get("do_not_optimize") or promotion_config.get(
+        "do-not-optimize", []
     )
-    rebuild_kinds = input.get('rebuild_kinds') or promotion_config.get('rebuild-kinds', [])
-    do_not_optimize = input.get('do_not_optimize') or promotion_config.get('do-not-optimize', [])
 
     # make parameters read-write
     parameters = dict(parameters)
     # Build previous_graph_ids from ``previous_graph_ids`` or ``revision``.
-    previous_graph_ids = input.get('previous_graph_ids')
+    previous_graph_ids = input.get("previous_graph_ids")
     if not previous_graph_ids:
         previous_graph_ids = [find_decision_task(parameters, graph_config)]
 
@@ -129,25 +151,31 @@ def release_promotion_action(parameters, graph_config, input, task_group_id, tas
         full_task_graph = get_artifact(graph_id, "public/full-task-graph.json")
         combined_full_task_graph.update(full_task_graph)
     _, combined_full_task_graph = TaskGraph.from_json(combined_full_task_graph)
-    parameters['existing_tasks'] = find_existing_tasks_from_previous_kinds(
+    parameters["existing_tasks"] = find_existing_tasks_from_previous_kinds(
         combined_full_task_graph, previous_graph_ids, rebuild_kinds
     )
-    parameters['do_not_optimize'] = do_not_optimize
-    parameters['target_tasks_method'] = target_tasks_method
-    parameters['build_number'] = int(input['build_number'])
+    parameters["do_not_optimize"] = do_not_optimize
+    parameters["target_tasks_method"] = target_tasks_method
+    parameters["build_number"] = int(input["build_number"])
     # When doing staging releases on try, we still want to re-use tasks from
     # previous graphs.
-    parameters['optimize_target_tasks'] = True
-    parameters['shipping_phase'] = input['release_promotion_flavor']
+    parameters["optimize_target_tasks"] = True
+    parameters["shipping_phase"] = input["release_promotion_flavor"]
 
     version_in_file = read_version_file()
-    parameters['version'] = input['version'] if input.get('version') else read_version_file()
-    version_string = parameters['version']
+    parameters["version"] = (
+        input["version"] if input.get("version") else read_version_file()
+    )
+    version_string = parameters["version"]
     if version_string != version_in_file:
-        raise ValueError("Version given in tag ({}) does not match the one in version.txt ({})".format(version_string, version_in_file))
-    parameters['head_tag'] = 'v{}'.format(version_string)
+        raise ValueError(
+            "Version given in tag ({}) does not match the one in version.txt ({})".format(
+                version_string, version_in_file
+            )
+        )
+    parameters["head_tag"] = "v{}".format(version_string)
 
-    parameters['next_version'] = input['next_version']
+    parameters["next_version"] = input["next_version"]
 
     version = FenixVersion.parse(version_string)
     if version.is_beta:
@@ -158,17 +186,17 @@ def release_promotion_action(parameters, graph_config, input, task_group_id, tas
         release_type = "release"
     else:
         raise ValueError("Unsupported version type: {}".format(version.version_type))
-    parameters['release_type'] = release_type
-    parameters['tasks_for'] = 'action'
+    parameters["release_type"] = release_type
+    parameters["tasks_for"] = "action"
 
-    parameters['pull_request_number'] = None
+    parameters["pull_request_number"] = None
 
     # make parameters read-only
     parameters = Parameters(**parameters)
 
-    taskgraph_decision({'root': graph_config.root_dir}, parameters=parameters)
+    taskgraph_decision({"root": graph_config.root_dir}, parameters=parameters)
 
 
 def read_version_file():
-    with open(os.path.join(os.path.dirname(__file__), '..', '..', 'version.txt')) as f:
+    with open(os.path.join(os.path.dirname(__file__), "..", "..", "version.txt")) as f:
         return f.read().strip()
diff --git a/taskcluster/fenix_taskgraph/routes.py b/taskcluster/fenix_taskgraph/routes.py
index 32892295e9..c4a1317b57 100644
--- a/taskcluster/fenix_taskgraph/routes.py
+++ b/taskcluster/fenix_taskgraph/routes.py
@@ -2,8 +2,6 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 import time
 
 from taskgraph.transforms.task import index_builder
diff --git a/taskcluster/fenix_taskgraph/target_tasks.py b/taskcluster/fenix_taskgraph/target_tasks.py
index bbeb45b29a..d78451d3ba 100644
--- a/taskcluster/fenix_taskgraph/target_tasks.py
+++ b/taskcluster/fenix_taskgraph/target_tasks.py
@@ -2,12 +2,10 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.target_tasks import _target_task
 
 
-@_target_task('release')
+@_target_task("release")
 def target_tasks_default(full_task_graph, parameters, graph_config):
 
     # TODO Use shipping-phase
@@ -35,7 +33,11 @@ def _filter_fennec(fennec_type, task, parameters):
 def target_tasks_fennec_nightly(full_task_graph, parameters, graph_config):
     """Select the set of tasks required for a production build signed with the fennec key."""
 
-    return [l for l, t in full_task_graph.tasks.items() if _filter_fennec("production", t, parameters)]
+    return [
+        l
+        for l, t in full_task_graph.tasks.items()
+        if _filter_fennec("production", t, parameters)
+    ]
 
 
 @_target_task("bump_android_components")
diff --git a/taskcluster/fenix_taskgraph/transforms/beetmover.py b/taskcluster/fenix_taskgraph/transforms/beetmover.py
index ccbb9d5103..8eaaf91fcd 100644
--- a/taskcluster/fenix_taskgraph/transforms/beetmover.py
+++ b/taskcluster/fenix_taskgraph/transforms/beetmover.py
@@ -5,15 +5,12 @@
 Transform the beetmover task into an actual task description.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
 import logging
 
-from six import text_type, ensure_text
-
 from taskgraph.util.schema import optionally_keyed_by, resolve_keyed_by
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.transforms.task import task_description_schema
-from voluptuous import Any, Optional, Required, Schema
+from voluptuous import Optional, Required, Schema
 
 from fenix_taskgraph.util.scriptworker import generate_beetmover_artifact_map
 
@@ -22,13 +19,13 @@ logger = logging.getLogger(__name__)
 beetmover_description_schema = Schema(
     {
         # unique name to describe this beetmover task, defaults to {dep.label}-beetmover
-        Required("name"): text_type,
+        Required("name"): str,
         Required("worker"): {"upstream-artifacts": [dict]},
         # treeherder is allowed here to override any defaults we use for beetmover.
         Optional("treeherder"): task_description_schema["treeherder"],
         Optional("attributes"): task_description_schema["attributes"],
         Optional("dependencies"): task_description_schema["dependencies"],
-        Optional("run-on-tasks-for"): [text_type],
+        Optional("run-on-tasks-for"): [str],
         Optional("bucket-scope"): optionally_keyed_by("level", "build-type", str),
     }
 )
@@ -43,25 +40,23 @@ def make_task_description(config, tasks):
         attributes = task["attributes"]
 
         label = "beetmover-{}".format(task["name"])
-        description = (
-            "Beetmover submission for build type '{build_type}'".format(
-                build_type=attributes.get("build-type"),
-            )
+        description = "Beetmover submission for build type '{build_type}'".format(
+            build_type=attributes.get("build-type"),
         )
 
         if task.get("locale"):
             attributes["locale"] = task["locale"]
 
         resolve_keyed_by(
-            task, 
+            task,
             "bucket-scope",
-            item_name=task['name'],
+            item_name=task["name"],
             **{
-                'build-type': task['attributes']['build-type'],
-                'level': config.params["level"]
+                "build-type": task["attributes"]["build-type"],
+                "level": config.params["level"],
             }
         )
-        bucket_scope = task.pop('bucket-scope')
+        bucket_scope = task.pop("bucket-scope")
 
         task = {
             "label": label,
@@ -85,10 +80,10 @@ def make_task_description(config, tasks):
 def craft_release_properties(config, task):
     params = config.params
     return {
-        "app-name": ensure_text(params["project"]),
-        "app-version": ensure_text(params["version"]),
-        "branch": ensure_text(params["project"]),
-        "build-id": ensure_text(params["moz_build_date"]),
+        "app-name": str(params["project"]),
+        "app-version": str(params["version"]),
+        "branch": str(params["project"]),
+        "build-id": str(params["moz_build_date"]),
         "hash-type": "sha512",
         "platform": "android",
     }
diff --git a/taskcluster/fenix_taskgraph/transforms/browsertime.py b/taskcluster/fenix_taskgraph/transforms/browsertime.py
index bf5274a891..bce1a4e96b 100644
--- a/taskcluster/fenix_taskgraph/transforms/browsertime.py
+++ b/taskcluster/fenix_taskgraph/transforms/browsertime.py
@@ -6,8 +6,6 @@ Apply some defaults and minor modifications to the jobs defined in the build
 kind.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 import copy
 import json
 
diff --git a/taskcluster/fenix_taskgraph/transforms/build.py b/taskcluster/fenix_taskgraph/transforms/build.py
index 20e93476f1..51c8bed35d 100644
--- a/taskcluster/fenix_taskgraph/transforms/build.py
+++ b/taskcluster/fenix_taskgraph/transforms/build.py
@@ -6,10 +6,6 @@ Apply some defaults and minor modifications to the jobs defined in the build
 kind.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
-import datetime
-
 from taskgraph.transforms.base import TransformSequence
 from fenix_taskgraph.gradle import get_variant
 
@@ -33,31 +29,49 @@ def add_shippable_secrets(config, tasks):
         secrets = task["run"].setdefault("secrets", [])
         dummy_secrets = task["run"].setdefault("dummy-secrets", [])
 
-        if task.pop("include-shippable-secrets", False) and config.params["level"] == "3":
+        if (
+            task.pop("include-shippable-secrets", False)
+            and config.params["level"] == "3"
+        ):
             build_type = task["attributes"]["build-type"]
             gradle_build_type = task["run"]["gradle-build-type"]
-            secret_index = 'project/mobile/fenix/{}'.format(build_type)
-            secrets.extend([{
-                "key": key,
-                "name": secret_index,
-                "path": target_file,
-            } for key, target_file in (
-                ('adjust', '.adjust_token'),
-                ('firebase', 'app/src/{}/res/values/firebase.xml'.format(gradle_build_type)),
-                ('sentry_dsn', '.sentry_token'),
-                ('mls', '.mls_token'),
-                ('nimbus_url', '.nimbus'),
-                ('wallpaper_url', ".wallpaper_url")
-            )])
+            secret_index = "project/mobile/fenix/{}".format(build_type)
+            secrets.extend(
+                [
+                    {
+                        "key": key,
+                        "name": secret_index,
+                        "path": target_file,
+                    }
+                    for key, target_file in (
+                        ("adjust", ".adjust_token"),
+                        (
+                            "firebase",
+                            "app/src/{}/res/values/firebase.xml".format(
+                                gradle_build_type
+                            ),
+                        ),
+                        ("sentry_dsn", ".sentry_token"),
+                        ("mls", ".mls_token"),
+                        ("nimbus_url", ".nimbus"),
+                        ("wallpaper_url", ".wallpaper_url"),
+                    )
+                ]
+            )
         else:
-            dummy_secrets.extend([{
-                "content": fake_value,
-                "path": target_file,
-            } for fake_value, target_file in (
-                ("faketoken", ".adjust_token"),
-                ("faketoken", ".mls_token"),
-                ("https://fake@sentry.prod.mozaws.net/368", ".sentry_token"),
-            )])
+            dummy_secrets.extend(
+                [
+                    {
+                        "content": fake_value,
+                        "path": target_file,
+                    }
+                    for fake_value, target_file in (
+                        ("faketoken", ".adjust_token"),
+                        ("faketoken", ".mls_token"),
+                        ("https://fake@sentry.prod.mozaws.net/368", ".sentry_token"),
+                    )
+                ]
+            )
 
         yield task
 
@@ -75,6 +89,7 @@ def build_gradle_command(config, tasks):
 
         yield task
 
+
 @transforms.add
 def track_apk_size(config, tasks):
     for task in tasks:
@@ -89,6 +104,7 @@ def track_apk_size(config, tasks):
 
         yield task
 
+
 @transforms.add
 def extra_gradle_options(config, tasks):
     for task in tasks:
@@ -97,14 +113,13 @@ def extra_gradle_options(config, tasks):
 
         yield task
 
+
 @transforms.add
 def add_test_build_type(config, tasks):
     for task in tasks:
         test_build_type = task["run"].pop("test-build-type", "")
         if test_build_type:
-            task["run"]["gradlew"].append(
-                "-PtestBuildType={}".format(test_build_type)
-            )
+            task["run"]["gradlew"].append("-PtestBuildType={}".format(test_build_type))
         yield task
 
 
@@ -120,11 +135,13 @@ def add_disable_optimization(config, tasks):
 def add_nightly_version(config, tasks):
     for task in tasks:
         if task.pop("include-nightly-version", False):
-            task["run"]["gradlew"].extend([
-                # We only set the `official` flag here. The actual version name will be determined
-                # by Gradle (depending on the Gecko/A-C version being used)
-                '-Pofficial'
-            ])
+            task["run"]["gradlew"].extend(
+                [
+                    # We only set the `official` flag here. The actual version name will be determined
+                    # by Gradle (depending on the Gecko/A-C version being used)
+                    "-Pofficial"
+                ]
+            )
         yield task
 
 
@@ -132,10 +149,9 @@ def add_nightly_version(config, tasks):
 def add_release_version(config, tasks):
     for task in tasks:
         if task.pop("include-release-version", False):
-            task["run"]["gradlew"].extend([
-                '-PversionName={}'.format(config.params["version"]),
-                '-Pofficial'
-            ])
+            task["run"]["gradlew"].extend(
+                ["-PversionName={}".format(config.params["version"]), "-Pofficial"]
+            )
         yield task
 
 
@@ -150,23 +166,21 @@ def add_artifacts(config, tasks):
         if "apk-artifact-template" in task:
             artifact_template = task.pop("apk-artifact-template")
             for apk in variant_config["apks"]:
-                apk_name = artifact_template["name"].format(
-                    **apk
+                apk_name = artifact_template["name"].format(**apk)
+                artifacts.append(
+                    {
+                        "type": artifact_template["type"],
+                        "name": apk_name,
+                        "path": artifact_template["path"].format(
+                            gradle_build_type=gradle_build_type, **apk
+                        ),
+                    }
                 )
-                artifacts.append({
-                    "type": artifact_template["type"],
-                    "name": apk_name,
-                    "path": artifact_template["path"].format(
-                        gradle_build_type=gradle_build_type,
-                        **apk
-                    ),
-                })
                 apks[apk["abi"]] = {
                     "name": apk_name,
                     "github-name": artifact_template["github-name"].format(
-                        version=config.params["version"],
-                        **apk
-                    )
+                        version=config.params["version"], **apk
+                    ),
                 }
 
         yield task
@@ -178,5 +192,7 @@ def filter_incomplete_translation(config, tasks):
         if task.pop("filter-incomplete-translations", False):
             # filter-release-translations modifies source, which could cause problems if we ever start caching source
             pre_gradlew = task["run"].setdefault("pre-gradlew", [])
-            pre_gradlew.append(["python", "automation/taskcluster/l10n/filter-release-translations.py"])
+            pre_gradlew.append(
+                ["python", "automation/taskcluster/l10n/filter-release-translations.py"]
+            )
         yield task
diff --git a/taskcluster/fenix_taskgraph/transforms/github_release.py b/taskcluster/fenix_taskgraph/transforms/github_release.py
index 153193f0f0..b5fb7bdb75 100644
--- a/taskcluster/fenix_taskgraph/transforms/github_release.py
+++ b/taskcluster/fenix_taskgraph/transforms/github_release.py
@@ -6,8 +6,6 @@ Apply some defaults and minor modifications to the jobs defined in the github_re
 kind.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.util.schema import resolve_keyed_by
 
@@ -18,14 +16,18 @@ transforms = TransformSequence()
 @transforms.add
 def resolve_keys(config, tasks):
     for task in tasks:
-        for key in ("worker.github-project", "worker.is-prerelease", "worker.release-name"):
+        for key in (
+            "worker.github-project",
+            "worker.is-prerelease",
+            "worker.release-name",
+        ):
             resolve_keyed_by(
                 task,
                 key,
                 item_name=task["name"],
                 **{
-                    'build-type': task["attributes"]["build-type"],
-                    'level': config.params["level"],
+                    "build-type": task["attributes"]["build-type"],
+                    "level": config.params["level"],
                 }
             )
         yield task
@@ -38,13 +40,16 @@ def build_worker_definition(config, tasks):
             "artifact-map": _build_artifact_map(task),
             "git-tag": config.params["head_tag"],
             "git-revision": config.params["head_rev"],
-            "release-name": task["worker"]["release-name"].format(version=config.params["version"]),
+            "release-name": task["worker"]["release-name"].format(
+                version=config.params["version"]
+            ),
         }
 
         task["worker"].update(worker_definition)
 
         yield task
 
+
 def _build_artifact_map(task):
     artifact_map = []
     github_names_per_path = {
@@ -55,9 +60,7 @@ def _build_artifact_map(task):
     for upstream_artifact_metadata in task["worker"]["upstream-artifacts"]:
         artifacts = {"paths": {}, "taskId": upstream_artifact_metadata["taskId"]}
         for path in upstream_artifact_metadata["paths"]:
-            artifacts["paths"][path] = {
-                "destinations": [github_names_per_path[path]]
-            }
+            artifacts["paths"][path] = {"destinations": [github_names_per_path[path]]}
 
         artifact_map.append(artifacts)
 
diff --git a/taskcluster/fenix_taskgraph/transforms/mark_as_shipped.py b/taskcluster/fenix_taskgraph/transforms/mark_as_shipped.py
index af44124fe3..9dc34eea51 100644
--- a/taskcluster/fenix_taskgraph/transforms/mark_as_shipped.py
+++ b/taskcluster/fenix_taskgraph/transforms/mark_as_shipped.py
@@ -6,8 +6,6 @@ Apply some defaults and minor modifications to the jobs defined in the build
 kind.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.util.schema import resolve_keyed_by
 
@@ -20,10 +18,10 @@ def resolve_keys(config, tasks):
     for task in tasks:
         resolve_keyed_by(
             task,
-            'scopes',
+            "scopes",
             item_name=task["name"],
             **{
-                'level': config.params["level"],
+                "level": config.params["level"],
             }
         )
         yield task
@@ -33,10 +31,12 @@ def resolve_keys(config, tasks):
 def make_task_description(config, jobs):
     for job in jobs:
         product = "Fenix"
-        version = config.params['version'] or "{ver}"
-        job['worker']['release-name'] = '{product}-{version}-build{build_number}'.format(
+        version = config.params["version"] or "{ver}"
+        job["worker"][
+            "release-name"
+        ] = "{product}-{version}-build{build_number}".format(
             product=product,
             version=version,
-            build_number=config.params.get('build_number', 1)
+            build_number=config.params.get("build_number", 1),
         )
         yield job
diff --git a/taskcluster/fenix_taskgraph/transforms/multi_dep.py b/taskcluster/fenix_taskgraph/transforms/multi_dep.py
index 76d28dd0a0..3b3783eeae 100644
--- a/taskcluster/fenix_taskgraph/transforms/multi_dep.py
+++ b/taskcluster/fenix_taskgraph/transforms/multi_dep.py
@@ -5,8 +5,6 @@
 Apply some defaults and minor modifications to the single_dep jobs.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.util.schema import resolve_keyed_by
 from taskgraph.util.treeherder import inherit_treeherder_from_dep, join_symbol
@@ -21,21 +19,20 @@ transforms = TransformSequence()
 def build_name_and_attributes(config, tasks):
     for task in tasks:
         task["dependencies"] = {
-            dep_key: dep.label
-            for dep_key, dep in _get_all_deps(task).items()
+            dep_key: dep.label for dep_key, dep in _get_all_deps(task).items()
         }
         primary_dep = task["primary-dependency"]
         copy_of_attributes = primary_dep.attributes.copy()
         task.setdefault("attributes", {}).update(copy_of_attributes)
         # run_on_tasks_for is set as an attribute later in the pipeline
-        task.setdefault("run-on-tasks-for", copy_of_attributes['run_on_tasks_for'])
+        task.setdefault("run-on-tasks-for", copy_of_attributes["run_on_tasks_for"])
         task["name"] = _get_dependent_job_name_without_its_kind(primary_dep)
 
         yield task
 
 
 def _get_dependent_job_name_without_its_kind(dependent_job):
-    return dependent_job.label[len(dependent_job.kind) + 1:]
+    return dependent_job.label[len(dependent_job.kind) + 1 :]
 
 
 def _get_all_deps(task):
@@ -53,8 +50,8 @@ def resolve_keys(config, tasks):
             "treeherder.job-symbol",
             item_name=task["name"],
             **{
-                'build-type': task["attributes"]["build-type"],
-                'level': config.params["level"],
+                "build-type": task["attributes"]["build-type"],
+                "level": config.params["level"],
             }
         )
         yield task
@@ -71,21 +68,25 @@ def build_upstream_artifacts(config, tasks):
             # Beetmover tasks use declarative artifacts.
             locale = task["attributes"].get("locale")
             build_type = task["attributes"]["build-type"]
-            worker_definition["upstream-artifacts"] = generate_beetmover_upstream_artifacts(
-                config, task, build_type, locale
-            )
+            worker_definition[
+                "upstream-artifacts"
+            ] = generate_beetmover_upstream_artifacts(config, task, build_type, locale)
         else:
             for dep in _get_all_deps(task).values():
-                paths = sorted([
-                    apk_metadata["name"]
-                    for apk_metadata in dep.attributes.get("apks", {}).values()
-                ])
+                paths = sorted(
+                    [
+                        apk_metadata["name"]
+                        for apk_metadata in dep.attributes.get("apks", {}).values()
+                    ]
+                )
                 if paths:
-                    worker_definition["upstream-artifacts"].append({
-                        "taskId": {"task-reference": "<{}>".format(dep.kind)},
-                        "taskType": dep.kind,
-                        "paths": paths,
-                    })
+                    worker_definition["upstream-artifacts"].append(
+                        {
+                            "taskId": {"task-reference": "<{}>".format(dep.kind)},
+                            "taskType": dep.kind,
+                            "paths": paths,
+                        }
+                    )
 
         task.setdefault("worker", {}).update(worker_definition)
         yield task
diff --git a/taskcluster/fenix_taskgraph/transforms/notify.py b/taskcluster/fenix_taskgraph/transforms/notify.py
index e3d7898d90..565da211ae 100644
--- a/taskcluster/fenix_taskgraph/transforms/notify.py
+++ b/taskcluster/fenix_taskgraph/transforms/notify.py
@@ -5,14 +5,7 @@
 Handle notifications like emails.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
-import copy
-import json
-
 from taskgraph.transforms.base import TransformSequence
-from taskgraph.util.treeherder import inherit_treeherder_from_dep
-from taskgraph.util.schema import resolve_keyed_by
 
 transforms = TransformSequence()
 
@@ -20,22 +13,24 @@ transforms = TransformSequence()
 @transforms.add
 def add_notify_email(config, tasks):
     for task in tasks:
-        notify = task.pop('notify', {})
-        email_config = notify.get('email')
+        notify = task.pop("notify", {})
+        email_config = notify.get("email")
         if email_config:
-            extra = task.setdefault('extra', {})
-            notify = extra.setdefault('notify', {})
-            notify['email'] = {
-                'content': email_config['content'],
-                'subject': email_config['subject'],
-                'link': email_config.get('link', None),
+            extra = task.setdefault("extra", {})
+            notify = extra.setdefault("notify", {})
+            notify["email"] = {
+                "content": email_config["content"],
+                "subject": email_config["subject"],
+                "link": email_config.get("link", None),
             }
 
-            routes = task.setdefault('routes', [])
-            routes.extend([
-                'notify.email.{}.on-{}'.format(address, reason)
-                for address in email_config['to-addresses']
-                for reason in email_config['on-reasons']
-            ])
+            routes = task.setdefault("routes", [])
+            routes.extend(
+                [
+                    "notify.email.{}.on-{}".format(address, reason)
+                    for address in email_config["to-addresses"]
+                    for reason in email_config["on-reasons"]
+                ]
+            )
 
         yield task
diff --git a/taskcluster/fenix_taskgraph/transforms/push_apk.py b/taskcluster/fenix_taskgraph/transforms/push_apk.py
index ea06d62633..8ebab6fccd 100644
--- a/taskcluster/fenix_taskgraph/transforms/push_apk.py
+++ b/taskcluster/fenix_taskgraph/transforms/push_apk.py
@@ -6,8 +6,6 @@ Apply some defaults and minor modifications to the jobs defined in the build
 kind.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.util.schema import resolve_keyed_by
 
@@ -24,8 +22,8 @@ def resolve_keys(config, tasks):
                 key,
                 item_name=task["name"],
                 **{
-                    'build-type': task["attributes"]["build-type"],
-                    'level': config.params["level"],
+                    "build-type": task["attributes"]["build-type"],
+                    "level": config.params["level"],
                 }
             )
         yield task
diff --git a/taskcluster/fenix_taskgraph/transforms/secrets.py b/taskcluster/fenix_taskgraph/transforms/secrets.py
index 2e4167727c..e76a140126 100644
--- a/taskcluster/fenix_taskgraph/transforms/secrets.py
+++ b/taskcluster/fenix_taskgraph/transforms/secrets.py
@@ -5,8 +5,6 @@
 Resolve secrets and dummy secrets
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.util.schema import resolve_keyed_by
 
@@ -19,9 +17,6 @@ def resolve_keys(config, tasks):
     for task in tasks:
         for key in ("run.secrets", "run.dummy-secrets"):
             resolve_keyed_by(
-                task,
-                key,
-                item_name=task["name"],
-                level=config.params["level"]
+                task, key, item_name=task["name"], level=config.params["level"]
             )
         yield task
diff --git a/taskcluster/fenix_taskgraph/transforms/signing.py b/taskcluster/fenix_taskgraph/transforms/signing.py
index 1e96a81bb8..83520c912e 100644
--- a/taskcluster/fenix_taskgraph/transforms/signing.py
+++ b/taskcluster/fenix_taskgraph/transforms/signing.py
@@ -6,8 +6,6 @@ Apply some defaults and minor modifications to the jobs defined in the build
 kind.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.util.schema import resolve_keyed_by
 
@@ -24,13 +22,14 @@ def resolve_keys(config, tasks):
                 key,
                 item_name=task["name"],
                 **{
-                    'build-type': task["attributes"]["build-type"],
-                    'level': config.params["level"],
-                    'tasks-for': config.params["tasks_for"],
+                    "build-type": task["attributes"]["build-type"],
+                    "level": config.params["level"],
+                    "tasks-for": config.params["tasks_for"],
                 }
             )
         yield task
 
+
 @transforms.add
 def set_worker_type(config, tasks):
     for task in tasks:
@@ -38,7 +37,14 @@ def set_worker_type(config, tasks):
         if (
             str(config.params["level"]) == "3"
             and task["attributes"]["build-type"]
-            in ("nightly", "beta", "release", "android-test-nightly", "beta-mozillaonline", "release-mozillaonline")
+            in (
+                "nightly",
+                "beta",
+                "release",
+                "android-test-nightly",
+                "beta-mozillaonline",
+                "release-mozillaonline",
+            )
             and config.params["tasks_for"] in ("cron", "action")
         ):
             worker_type = "signing"
@@ -50,13 +56,18 @@ def set_worker_type(config, tasks):
 def set_signing_type(config, tasks):
     for task in tasks:
         signing_type = "dep-signing"
-        if (
-            str(config.params["level"]) == "3"
-            and config.params["tasks_for"] in ("cron", "action")
+        if str(config.params["level"]) == "3" and config.params["tasks_for"] in (
+            "cron",
+            "action",
         ):
             if task["attributes"]["build-type"] in ("beta", "release"):
                 signing_type = "fennec-production-signing"
-            elif task["attributes"]["build-type"] in ("nightly", "android-test-nightly", "beta-mozillaonline", "release-mozillaonline"):
+            elif task["attributes"]["build-type"] in (
+                "nightly",
+                "android-test-nightly",
+                "beta-mozillaonline",
+                "release-mozillaonline",
+            ):
                 signing_type = "production-signing"
         task.setdefault("worker", {})["signing-type"] = signing_type
         yield task
@@ -66,11 +77,9 @@ def set_signing_type(config, tasks):
 def set_index(config, tasks):
     for task in tasks:
         index = {}
-        if (
-            config.params["tasks_for"] in ("cron", "action")
-            and task["attributes"]["build-type"]
-            in ("nightly", "debut", "nightly-simulation", "beta", "release")
-        ):
+        if config.params["tasks_for"] in ("cron", "action") and task["attributes"][
+            "build-type"
+        ] in ("nightly", "debut", "nightly-simulation", "beta", "release"):
             index["type"] = "signing"
         task["index"] = index
         yield task
diff --git a/taskcluster/fenix_taskgraph/transforms/test.py b/taskcluster/fenix_taskgraph/transforms/test.py
index bbf7b8f2d8..66da07a0d1 100644
--- a/taskcluster/fenix_taskgraph/transforms/test.py
+++ b/taskcluster/fenix_taskgraph/transforms/test.py
@@ -2,8 +2,6 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.base import TransformSequence
 
 
@@ -15,6 +13,8 @@ def add_pr_number(config, tasks):
     for task in tasks:
         include_pr = task.pop("include-pull-request-number")
         if include_pr and config.params["pull_request_number"]:
-            task["worker"]["env"]["PULL_REQUEST_NUMBER"] = str(config.params["pull_request_number"])
+            task["worker"]["env"]["PULL_REQUEST_NUMBER"] = str(
+                config.params["pull_request_number"]
+            )
 
         yield task
diff --git a/taskcluster/fenix_taskgraph/transforms/version_bump.py b/taskcluster/fenix_taskgraph/transforms/version_bump.py
index c6a33f74f7..bbfdae2234 100644
--- a/taskcluster/fenix_taskgraph/transforms/version_bump.py
+++ b/taskcluster/fenix_taskgraph/transforms/version_bump.py
@@ -6,8 +6,6 @@ Apply some defaults and minor modifications to the jobs defined in the version b
 kind.
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.util.schema import resolve_keyed_by
 
@@ -24,8 +22,8 @@ def resolve_keys(config, tasks):
                 key,
                 item_name=task["name"],
                 **{
-                    'build-type': task["attributes"]["build-type"],
-                    'level': config.params["level"],
+                    "build-type": task["attributes"]["build-type"],
+                    "level": config.params["level"],
                 }
             )
         yield task
diff --git a/taskcluster/fenix_taskgraph/transforms/visual_metrics.py b/taskcluster/fenix_taskgraph/transforms/visual_metrics.py
index 6a2a7950d9..fdec58a70d 100644
--- a/taskcluster/fenix_taskgraph/transforms/visual_metrics.py
+++ b/taskcluster/fenix_taskgraph/transforms/visual_metrics.py
@@ -5,9 +5,6 @@
 Generate labels for tasks without names, consistently.
 Uses attributes from `primary-dependency`.
 """
-from __future__ import absolute_import, print_function, unicode_literals
-
-import os
 
 from taskgraph.transforms.base import TransformSequence
 
@@ -20,31 +17,33 @@ LABEL = "test-vismet-{platform}-{label}"
 
 @transforms.add
 def make_label(config, jobs):
-    """ Generate a sane label for a new task constructed from a dependency
+    """Generate a sane label for a new task constructed from a dependency
     Using attributes from the dependent job and the current task kind"""
     for job in jobs:
-        dep_job = job['primary-dependency']
+        dep_job = job["primary-dependency"]
         attr = dep_job.attributes.get
 
-        if attr('locale', job.get('locale')):
+        if attr("locale", job.get("locale")):
             template = "{kind}-{locale}-{build_platform}/{build_type}"
-        elif attr('l10n_chunk'):
+        elif attr("l10n_chunk"):
             template = "{kind}-{build_platform}-{l10n_chunk}/{build_type}"
-        elif config.kind.startswith("release-eme-free") or \
-                config.kind.startswith("release-partner-repack"):
-            suffix = job.get("extra", {}).get("repack_suffix", None) or \
-                     job.get("extra", {}).get("repack_id", None)
+        elif config.kind.startswith("release-eme-free") or config.kind.startswith(
+            "release-partner-repack"
+        ):
+            suffix = job.get("extra", {}).get("repack_suffix", None) or job.get(
+                "extra", {}
+            ).get("repack_id", None)
             template = "{kind}-{build_platform}"
             if suffix:
-                template += "-{}".format(suffix.replace('/', '-'))
+                template += "-{}".format(suffix.replace("/", "-"))
         else:
             template = "{kind}-{build_platform}/{build_type}"
-        job['label'] = template.format(
+        job["label"] = template.format(
             kind=config.kind,
-            build_platform=attr('build_platform'),
-            build_type=attr('build_type'),
-            locale=attr('locale', job.get('locale', '')),  # Locale can be absent
-            l10n_chunk=attr('l10n_chunk', '')  # Can be empty
+            build_platform=attr("build_platform"),
+            build_type=attr("build_type"),
+            locale=attr("locale", job.get("locale", "")),  # Locale can be absent
+            l10n_chunk=attr("l10n_chunk", ""),  # Can be empty
         )
 
         yield job
@@ -53,41 +52,40 @@ def make_label(config, jobs):
 @transforms.add
 def run_visual_metrics(config, jobs):
     for job in jobs:
-        dep_job = job.pop('primary-dependency', None)
+        dep_job = job.pop("primary-dependency", None)
         if dep_job is not None:
-            platform = dep_job.task['extra']['treeherder-platform']
-            job['dependencies'] = {dep_job.label: dep_job.label}
+            platform = dep_job.task["extra"]["treeherder-platform"]
+            job["dependencies"] = {dep_job.label: dep_job.label}
 
             # Add the artifact to be processed as a fetches artifact
-            job['fetches'][dep_job.label] = [{
-                'artifact': 'browsertime-results.tgz',
-                'extract': True
-            }]
+            job["fetches"][dep_job.label] = [
+                {"artifact": "browsertime-results.tgz", "extract": True}
+            ]
 
             # vismet runs on Linux but we want to have it displayed
             # alongside the job it was triggered by to make it easier for
             # people to find it back.
-            job['label'] = LABEL.format(platform=platform, label=dep_job.label)
-            treeherder_info = dict(dep_job.task['extra']['treeherder'])
-            job['treeherder']['platform'] = platform
-            job['treeherder']['symbol'] = SYMBOL.format(
-                groupSymbol=treeherder_info['groupSymbol'],
-                symbol=treeherder_info['symbol']
+            job["label"] = LABEL.format(platform=platform, label=dep_job.label)
+            treeherder_info = dict(dep_job.task["extra"]["treeherder"])
+            job["treeherder"]["platform"] = platform
+            job["treeherder"]["symbol"] = SYMBOL.format(
+                groupSymbol=treeherder_info["groupSymbol"],
+                symbol=treeherder_info["symbol"],
             )
 
             # Store the platform name so we can use it to calculate
             # the similarity metric against other tasks
-            job['worker'].setdefault('env', {})['TC_PLATFORM'] = platform
+            job["worker"].setdefault("env", {})["TC_PLATFORM"] = platform
 
             # run-on-projects needs to be set based on the dependent task
             attributes = dict(dep_job.attributes)
-            job['run-on-projects'] = attributes['run_on_projects']
+            job["run-on-projects"] = attributes["run_on_projects"]
 
             # The run-on-tasks-for also needs to be setup here
-            job['run-on-tasks-for'] = attributes.get('run_on_tasks_for', [])
+            job["run-on-tasks-for"] = attributes.get("run_on_tasks_for", [])
 
             # We can't use the multi_dep transforms which remove this
             # field, so we remove the dependent-tasks entry here
-            del job['dependent-tasks']
+            del job["dependent-tasks"]
 
             yield job
diff --git a/taskcluster/fenix_taskgraph/util/scriptworker.py b/taskcluster/fenix_taskgraph/util/scriptworker.py
index e4bdfa7c2c..95aa99aab6 100644
--- a/taskcluster/fenix_taskgraph/util/scriptworker.py
+++ b/taskcluster/fenix_taskgraph/util/scriptworker.py
@@ -2,8 +2,6 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
 import itertools
 import os
 from copy import deepcopy
@@ -44,7 +42,7 @@ def generate_beetmover_upstream_artifacts(
         **{
             "release-type": config.params["release_type"],
             "platform": platform,
-        }
+        },
     )
     map_config = deepcopy(cached_load_yaml(job["attributes"]["artifact_map"]))
     upstream_artifacts = list()
@@ -153,7 +151,7 @@ def generate_beetmover_artifact_map(config, job, **kwargs):
         **{
             "release-type": config.params["release_type"],
             "platform": platform,
-        }
+        },
     )
     map_config = deepcopy(cached_load_yaml(job["attributes"]["artifact_map"]))
     base_artifact_prefix = map_config.get(
@@ -176,9 +174,7 @@ def generate_beetmover_artifact_map(config, job, **kwargs):
         map_config,
         "s3_bucket_paths",
         job["label"],
-        **{
-            "build-type": job["attributes"]["build-type"]
-        }
+        **{"build-type": job["attributes"]["build-type"]},
     )
 
     for locale, dep in sorted(itertools.product(locales, dependencies)):
@@ -218,12 +214,7 @@ def generate_beetmover_artifact_map(config, job, **kwargs):
                 "pretty_name",
                 "checksums_path",
             ]:
-                resolve_keyed_by(
-                    file_config,
-                    field,
-                    job["label"],
-                    locale=locale
-                )
+                resolve_keyed_by(file_config, field, job["label"], locale=locale)
 
             # This format string should ideally be in the configuration file,
             # but this would mean keeping variable names in sync between code + config.
@@ -271,20 +262,16 @@ def generate_beetmover_artifact_map(config, job, **kwargs):
 
         version = read_version_file()
         upload_date = datetime.fromtimestamp(config.params["build_date"])
-        
+
         if job["attributes"]["build-type"] == "nightly":
             folder_prefix = upload_date.strftime("%Y/%m/%Y-%m-%d-%H-%M-%S-")
             # TODO: Remove this when version.txt has versioning fixed
-            version = version.split('-')[0]
+            version = version.split("-")[0]
         else:
             folder_prefix = f"{version}/android/"
 
         kwargs.update(
-            {
-                "locale": locale,
-                "version": version,
-                "folder_prefix": folder_prefix
-            }
+            {"locale": locale, "version": version, "folder_prefix": folder_prefix}
         )
         kwargs.update(**platforms)
         paths = jsone.render(paths, kwargs)
diff --git a/taskcluster/fenix_taskgraph/worker_types.py b/taskcluster/fenix_taskgraph/worker_types.py
index 3c36a63aa0..dfc5e80094 100644
--- a/taskcluster/fenix_taskgraph/worker_types.py
+++ b/taskcluster/fenix_taskgraph/worker_types.py
@@ -2,10 +2,6 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from __future__ import absolute_import, print_function, unicode_literals
-
-from six import text_type
-
 from voluptuous import Any, Required, Optional
 
 from taskgraph.util.schema import taskref_or_string
@@ -17,18 +13,18 @@ from taskgraph.transforms.task import payload_builder
     schema={
         # the maximum time to run, in seconds
         Required("max-run-time"): int,
-        Required("signing-type"): text_type,
+        Required("signing-type"): str,
         # list of artifact URLs for the artifacts that should be signed
         Required("upstream-artifacts"): [
             {
                 # taskId of the task with the artifact
                 Required("taskId"): taskref_or_string,
                 # type of signing task (for CoT)
-                Required("taskType"): text_type,
+                Required("taskType"): str,
                 # Paths to the artifacts to sign
-                Required("paths"): [text_type],
+                Required("paths"): [str],
                 # Signing formats to use on each of the paths
-                Required("formats"): [text_type],
+                Required("formats"): [str],
             }
         ],
     },
@@ -62,23 +58,27 @@ def build_scriptworker_signing_payload(config, task, task_def):
 @payload_builder(
     "scriptworker-beetmover",
     schema={
-        Required("action"): text_type,
-        Required("version"): text_type,
-        Required("artifact-map"): [{
-            Required("paths"): {
-                Any(text_type): {
-                    Required("destinations"): [text_type],
+        Required("action"): str,
+        Required("version"): str,
+        Required("artifact-map"): [
+            {
+                Required("paths"): {
+                    Any(str): {
+                        Required("destinations"): [str],
+                    },
                 },
-            },
-            Required("taskId"): taskref_or_string,
-        }],
-        Required("beetmover-application-name"): text_type,
-        Required("bucket"): text_type,
-        Required("upstream-artifacts"): [{
-            Required("taskId"): taskref_or_string,
-            Required("taskType"): text_type,
-            Required("paths"): [text_type],
-        }],
+                Required("taskId"): taskref_or_string,
+            }
+        ],
+        Required("beetmover-application-name"): str,
+        Required("bucket"): str,
+        Required("upstream-artifacts"): [
+            {
+                Required("taskId"): taskref_or_string,
+                Required("taskType"): str,
+                Required("paths"): [str],
+            }
+        ],
     },
 )
 def build_scriptworker_beetmover_payload(config, task, task_def):
@@ -96,14 +96,16 @@ def build_scriptworker_beetmover_payload(config, task, task_def):
         "artifactMap": worker["artifact-map"],
         "releaseProperties": {"appName": worker.pop("beetmover-application-name")},
         "upstreamArtifacts": worker["upstream-artifacts"],
-        "version": worker["version"]
+        "version": worker["version"],
     }
 
     scope_prefix = config.graph_config["scriptworker"]["scope-prefix"]
-    task_def["scopes"].extend([
-        "{}:beetmover:action:{}".format(scope_prefix, worker["action"]),
-        "{}:beetmover:bucket:{}".format(scope_prefix, worker["bucket"]),
-    ])
+    task_def["scopes"].extend(
+        [
+            "{}:beetmover:action:{}".format(scope_prefix, worker["action"]),
+            "{}:beetmover:bucket:{}".format(scope_prefix, worker["bucket"]),
+        ]
+    )
 
 
 @payload_builder(
@@ -112,16 +114,16 @@ def build_scriptworker_beetmover_payload(config, task, task_def):
         Required("upstream-artifacts"): [
             {
                 Required("taskId"): taskref_or_string,
-                Required("taskType"): text_type,
-                Required("paths"): [text_type],
+                Required("taskType"): str,
+                Required("paths"): [str],
             }
         ],
-        Required("certificate-alias"): text_type,
-        Required("channel"): text_type,
+        Required("certificate-alias"): str,
+        Required("channel"): str,
         Required("commit"): bool,
-        Required("product"): text_type,
+        Required("product"): str,
         Required("dep"): bool,
-        Optional("google-play-track"): text_type,
+        Optional("google-play-track"): str,
     },
 )
 def build_push_apk_payload(config, task, task_def):
@@ -152,11 +154,11 @@ def build_push_apk_payload(config, task, task_def):
         Required("upstream-artifacts"): [
             {
                 Required("taskId"): taskref_or_string,
-                Required("taskType"): text_type,
-                Required("paths"): [text_type],
+                Required("taskType"): str,
+                Required("paths"): [str],
             }
         ],
-        Required("release-name"): text_type,
+        Required("release-name"): str,
     },
 )
 def build_shipit_payload(config, task, task_def):
@@ -164,9 +166,7 @@ def build_shipit_payload(config, task, task_def):
 
     task_def["tags"]["worker-implementation"] = "scriptworker"
 
-    task_def['payload'] = {
-        'release_name': worker['release-name']
-    }
+    task_def["payload"] = {"release_name": worker["release-name"]}
 
 
 @payload_builder(
@@ -175,17 +175,17 @@ def build_shipit_payload(config, task, task_def):
         Required("upstream-artifacts"): [
             {
                 Required("taskId"): taskref_or_string,
-                Required("taskType"): text_type,
-                Required("paths"): [text_type],
+                Required("taskType"): str,
+                Required("paths"): [str],
             }
         ],
         Required("artifact-map"): [object],
-        Required("action"): text_type,
-        Required("git-tag"): text_type,
-        Required("git-revision"): text_type,
-        Required("github-project"): text_type,
+        Required("action"): str,
+        Required("git-tag"): str,
+        Required("git-revision"): str,
+        Required("github-project"): str,
         Required("is-prerelease"): bool,
-        Required("release-name"): text_type,
+        Required("release-name"): str,
     },
 )
 def build_github_release_payload(config, task, task_def):
@@ -203,10 +203,12 @@ def build_github_release_payload(config, task, task_def):
     }
 
     scope_prefix = config.graph_config["scriptworker"]["scope-prefix"]
-    task_def["scopes"].extend([
-        "{}:github:project:{}".format(scope_prefix, worker["github-project"]),
-        "{}:github:action:{}".format(scope_prefix, worker["action"]),
-    ])
+    task_def["scopes"].extend(
+        [
+            "{}:github:project:{}".format(scope_prefix, worker["github-project"]),
+            "{}:github:action:{}".format(scope_prefix, worker["action"]),
+        ]
+    )
 
 
 @payload_builder(
@@ -215,38 +217,38 @@ def build_github_release_payload(config, task, task_def):
         Optional("upstream-artifacts"): [
             {
                 Optional("taskId"): taskref_or_string,
-                Optional("taskType"): text_type,
-                Optional("paths"): [text_type],
+                Optional("taskType"): str,
+                Optional("paths"): [str],
             }
         ],
         Required("bump"): bool,
-        Optional("bump-files"): [text_type],
+        Optional("bump-files"): [str],
         Optional("push"): bool,
-        Optional("branch"): text_type,
+        Optional("branch"): str,
     },
 )
 def build_version_bump_payload(config, task, task_def):
     worker = task["worker"]
     task_def["tags"]["worker-implementation"] = "scriptworker"
 
-    task_def['payload'] = {'actions': []}
-    actions = task_def['payload']['actions']
+    task_def["payload"] = {"actions": []}
+    actions = task_def["payload"]["actions"]
 
-    if worker['bump']:
-        if not worker['bump-files']:
+    if worker["bump"]:
+        if not worker["bump-files"]:
             raise Exception("Version Bump requested without bump-files")
 
         bump_info = {}
         bump_info["next_version"] = config.params["next_version"]
-        bump_info['files'] = worker['bump-files']
-        task_def['payload']['version_bump_info'] = bump_info
-        actions.append('version_bump')
+        bump_info["files"] = worker["bump-files"]
+        task_def["payload"]["version_bump_info"] = bump_info
+        actions.append("version_bump")
 
     if worker["push"]:
-        task_def['payload']['push'] = True
+        task_def["payload"]["push"] = True
 
-    if worker.get('force-dry-run'):
-        task_def['payload']['dry_run'] = True
+    if worker.get("force-dry-run"):
+        task_def["payload"]["dry_run"] = True
 
     if worker.get("branch"):
         task_def["payload"]["branch"] = worker["branch"]
diff --git a/taskcluster/requirements.in b/taskcluster/requirements.in
new file mode 100644
index 0000000000..5ff4275e9b
--- /dev/null
+++ b/taskcluster/requirements.in
@@ -0,0 +1,5 @@
+# For instructions on managing dependencies, see:
+# https://taskcluster-taskgraph.readthedocs.io/en/latest/howto/bootstrap-taskgraph.html
+
+taskcluster-taskgraph>=1.3.0
+mozilla-version
\ No newline at end of file
diff --git a/taskcluster/requirements.txt b/taskcluster/requirements.txt
new file mode 100644
index 0000000000..520caacf6e
--- /dev/null
+++ b/taskcluster/requirements.txt
@@ -0,0 +1,106 @@
+#
+# This file is autogenerated by pip-compile with python 3.6
+# To update, run:
+#
+#    pip-compile --generate-hashes --output-file=requirements.txt requirements.in
+#
+appdirs==1.4.4 \
+    --hash=sha256:7d5d0167b2b1ba821647616af46a749d1c653740dd0d2415100fe26e27afdf41 \
+    --hash=sha256:a841dacd6b99318a741b166adb07e19ee71a274450e68237b4650ca1055ab128
+    # via taskcluster-taskgraph
+attrs==21.4.0 \
+    --hash=sha256:2d27e3784d7a565d36ab851fe94887c5eccd6a463168875832a1be79c82828b4 \
+    --hash=sha256:626ba8234211db98e869df76230a137c4c40a12d72445c45d5f5b716f076e2fd
+    # via
+    #   mozilla-version
+    #   taskcluster-taskgraph
+certifi==2021.10.8 \
+    --hash=sha256:78884e7c1d4b00ce3cea67b44566851c4343c120abd683433ce934a68ea58872 \
+    --hash=sha256:d62a0163eb4c2344ac042ab2bdf75399a71a2d8c7d47eac2e2ee91b9d6339569
+    # via requests
+charset-normalizer==2.0.12 \
+    --hash=sha256:2857e29ff0d34db842cd7ca3230549d1a697f96ee6d3fb071cfa6c7393832597 \
+    --hash=sha256:6881edbebdb17b39b4eaaa821b438bf6eddffb4468cf344f09f89def34a8b1df
+    # via requests
+future==0.18.2 \
+    --hash=sha256:b1bead90b70cf6ec3f0710ae53a525360fa360d306a86583adc6bf83a4db537d
+    # via mozilla-version
+idna==3.3 \
+    --hash=sha256:84d9dd047ffa80596e0f246e2eab0b391788b0503584e8945f2368256d2735ff \
+    --hash=sha256:9d643ff0a55b762d5cdb124b8eaa99c66322e2157b69160bc32796e824360e6d
+    # via requests
+json-e==4.4.3 \
+    --hash=sha256:8ed3974faa887ca96a7987298f6550cf2ad35472419a980766b3abe48258de0a
+    # via taskcluster-taskgraph
+mozilla-version==1.0.0 \
+    --hash=sha256:678093aacc455a49b6feb6eeb922296c191aca4884e815573156b5966b8b051e \
+    --hash=sha256:a6d06ac135dd6f4333b9ac1fd04f41f4ba96e83973dd2ac9f70daf577718b96c
+    # via -r requirements.in
+pyyaml==6.0 \
+    --hash=sha256:0283c35a6a9fbf047493e3a0ce8d79ef5030852c51e9d911a27badfde0605293 \
+    --hash=sha256:055d937d65826939cb044fc8c9b08889e8c743fdc6a32b33e2390f66013e449b \
+    --hash=sha256:07751360502caac1c067a8132d150cf3d61339af5691fe9e87803040dbc5db57 \
+    --hash=sha256:0b4624f379dab24d3725ffde76559cff63d9ec94e1736b556dacdfebe5ab6d4b \
+    --hash=sha256:0ce82d761c532fe4ec3f87fc45688bdd3a4c1dc5e0b4a19814b9009a29baefd4 \
+    --hash=sha256:1e4747bc279b4f613a09eb64bba2ba602d8a6664c6ce6396a4d0cd413a50ce07 \
+    --hash=sha256:213c60cd50106436cc818accf5baa1aba61c0189ff610f64f4a3e8c6726218ba \
+    --hash=sha256:231710d57adfd809ef5d34183b8ed1eeae3f76459c18fb4a0b373ad56bedcdd9 \
+    --hash=sha256:277a0ef2981ca40581a47093e9e2d13b3f1fbbeffae064c1d21bfceba2030287 \
+    --hash=sha256:2cd5df3de48857ed0544b34e2d40e9fac445930039f3cfe4bcc592a1f836d513 \
+    --hash=sha256:40527857252b61eacd1d9af500c3337ba8deb8fc298940291486c465c8b46ec0 \
+    --hash=sha256:473f9edb243cb1935ab5a084eb238d842fb8f404ed2193a915d1784b5a6b5fc0 \
+    --hash=sha256:48c346915c114f5fdb3ead70312bd042a953a8ce5c7106d5bfb1a5254e47da92 \
+    --hash=sha256:50602afada6d6cbfad699b0c7bb50d5ccffa7e46a3d738092afddc1f9758427f \
+    --hash=sha256:68fb519c14306fec9720a2a5b45bc9f0c8d1b9c72adf45c37baedfcd949c35a2 \
+    --hash=sha256:77f396e6ef4c73fdc33a9157446466f1cff553d979bd00ecb64385760c6babdc \
+    --hash=sha256:819b3830a1543db06c4d4b865e70ded25be52a2e0631ccd2f6a47a2822f2fd7c \
+    --hash=sha256:897b80890765f037df3403d22bab41627ca8811ae55e9a722fd0392850ec4d86 \
+    --hash=sha256:98c4d36e99714e55cfbaaee6dd5badbc9a1ec339ebfc3b1f52e293aee6bb71a4 \
+    --hash=sha256:9df7ed3b3d2e0ecfe09e14741b857df43adb5a3ddadc919a2d94fbdf78fea53c \
+    --hash=sha256:9fa600030013c4de8165339db93d182b9431076eb98eb40ee068700c9c813e34 \
+    --hash=sha256:a80a78046a72361de73f8f395f1f1e49f956c6be882eed58505a15f3e430962b \
+    --hash=sha256:b3d267842bf12586ba6c734f89d1f5b871df0273157918b0ccefa29deb05c21c \
+    --hash=sha256:b5b9eccad747aabaaffbc6064800670f0c297e52c12754eb1d976c57e4f74dcb \
+    --hash=sha256:c5687b8d43cf58545ade1fe3e055f70eac7a5a1a0bf42824308d868289a95737 \
+    --hash=sha256:cba8c411ef271aa037d7357a2bc8f9ee8b58b9965831d9e51baf703280dc73d3 \
+    --hash=sha256:d15a181d1ecd0d4270dc32edb46f7cb7733c7c508857278d3d378d14d606db2d \
+    --hash=sha256:d4db7c7aef085872ef65a8fd7d6d09a14ae91f691dec3e87ee5ee0539d516f53 \
+    --hash=sha256:d4eccecf9adf6fbcc6861a38015c2a64f38b9d94838ac1810a9023a0609e1b78 \
+    --hash=sha256:d67d839ede4ed1b28a4e8909735fc992a923cdb84e618544973d7dfc71540803 \
+    --hash=sha256:daf496c58a8c52083df09b80c860005194014c3698698d1a57cbcfa182142a3a \
+    --hash=sha256:e61ceaab6f49fb8bdfaa0f92c4b57bcfbea54c09277b1b4f7ac376bfb7a7c174 \
+    --hash=sha256:f84fbc98b019fef2ee9a1cb3ce93e3187a6df0b2538a651bfb890254ba9f90b5
+    # via taskcluster-taskgraph
+redo==2.0.4 \
+    --hash=sha256:81066955041c853b0e6491eb65a0877dce45131c4cfa3d42d923fc2aa8f7a043
+    # via taskcluster-taskgraph
+requests==2.27.1 \
+    --hash=sha256:68d7c56fd5a8999887728ef304a6d12edc7be74f1cfa47714fc8b414525c9a61 \
+    --hash=sha256:f22fa1e554c9ddfd16e6e41ac79759e17be9e492b3587efa038054674760e72d
+    # via
+    #   requests-unixsocket
+    #   taskcluster-taskgraph
+requests-unixsocket==0.3.0 \
+    --hash=sha256:28304283ea9357d45fff58ad5b11e47708cfbf5806817aa59b2a363228ee971e \
+    --hash=sha256:c685c680f0809e1b2955339b1e5afc3c0022b3066f4f7eb343f43a6065fc0e5d
+    # via taskcluster-taskgraph
+slugid==2.0.0 \
+    --hash=sha256:a950d98b72691178bdd4d6c52743c4a2aa039207cf7a97d71060a111ff9ba297 \
+    --hash=sha256:aec8b0e01c4ad32e38e12d609eab3ec912fd129aaf6b2ded0199b56a5f8fd67c
+    # via taskcluster-taskgraph
+taskcluster-taskgraph==1.3.0 \
+    --hash=sha256:a1050f8a613e31fcd7bc4fed85e07e57baa5675a5a5719065caebada533eb8f5 \
+    --hash=sha256:bd3c35d82296c323064c8b6e6d4a88ab186bcd872bdd930bfe734a0b2525a082
+    # via -r requirements.in
+taskcluster-urls==13.0.1 \
+    --hash=sha256:5e25e7e6818e8877178b175ff43d2e6548afad72694aa125f404a7329ece0973 \
+    --hash=sha256:b25e122ecec249c4299ac7b20b08db76e3e2025bdaeb699a9d444556de5fd367 \
+    --hash=sha256:f66dcbd6572a6216ab65949f0fa0b91f2df647918028436c384e6af5cd12ae2b
+    # via taskcluster-taskgraph
+urllib3==1.26.8 \
+    --hash=sha256:000ca7f471a233c2251c6c7023ee85305721bfdf18621ebff4fd17a8653427ed \
+    --hash=sha256:0e7c33d9a63e7ddfcb86780aac87befc2fbddf46c58dbb487e0855f7ceec283c
+    # via requests
+voluptuous==0.12.2 \
+    --hash=sha256:4db1ac5079db9249820d49c891cb4660a6f8cae350491210abce741fabf56513
+    # via taskcluster-taskgraph