Cirrus: Add root to subuid/subgid list

Fixes
https://gitlab.torproject.org/tpo/applications/tor-browser-build/-/issues/40298

tools/add-root-subids.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+
+def add_subid(baseid: str, filename: str):
+    mapid = 100000
+    countid = 65536
+
+    with open(filename, "r") as f:
+        for line in f:
+            line_baseid, line_mapid, line_countid = line.split(":")
+            line_mapid = int(line_mapid)
+            line_countid = int(line_countid)
+
+            if line_baseid == baseid:
+                return
+
+            mapid = max(mapid, line_mapid + line_countid)
+
+    with open(filename, "a") as f:
+        f.write(f"{baseid}:{mapid}:{countid}\n")
+
+add_subid("root", "/etc/subuid")
+add_subid("root", "/etc/subgid")

tools/cirrus_build_project.sh

@@ -36,6 +36,9 @@ cat tools/rbm.local.conf.onetarget | sed "s/CHANNEL/$CHANNEL/g" | sed "s/ncdns-a
 echo "Patching rbm..."
 ./tools/patch-tor-to-namecoin.sh
 
+echo "Mapping subid's..."
+./tools/add-root-subids.py
+
 if [[ "$BUMP_DEPS" -eq 1 ]]; then
     ./tools/namecoin-bump-versions.sh
     exit 0