These instructions are intended to build the emulator in Linux and macOS. Windows users are suggested to develop in a [Linux VM](https://www.howtogeek.com/howto/11287/how-to-run-ubuntu-in-windows-7-with-vmware-player/) or using the [Windows Subsystem for Linux](https://en.wikipedia.org/wiki/Windows_Subsystem_for_Linux).
If you only want to work with Lua frontend stuff, you can grab the AppImage and
run it with `--appimage-extract`.
You can skip most of the following instructions if desired, and use our premade Docker image instead. In that case the only requirements are Git and Docker. See [the virtual development environment README](https://github.com/koreader/virdevenv) for more information.
**Note:** If you want to use WSL then you'll need to export a sane PATH first, because Windows appends its own directories to it. You'll also need to [install an XServer](https://virtualizationreview.com/articles/2017/02/08/graphical-programs-on-windows-subsystem-on-linux.aspx). If you need more info please read <https://github.com/koreader/koreader/issues/6354>.
*Note:* With current XCode versions, you *will* need to set a minimum deployment version higher than `10.04`. Otherwise, you'll hit various linking errors related to missing unwinding libraries/symbols.
On Mojave, `10.09` has been known to behave with XCode 10, And `10.14` with XCode 11. When in doubt, go with your current macOS version.
*Note:* On Catalina (10.15), you will currently *NOT* want to deploy for `10.15`, as [XCode is currently broken in that configuration](https://forums.developer.apple.com/thread/121887)! (i.e., deploy for `10.14` instead).
*Note:* On macOS and possibly other non-Linux hosts, you might want to pass `--no-build` to prevent re-running the buildsystem, as incremental builds may not behave properly.
Briefly, you need to install `luarocks` and then install `busted` and `ansicolors` with `luarocks`. The "eng" language data file for tesseract-ocr is also need to test OCR functionality. Finally, make sure that `luajit` in your system is at least of version 2.0.2.
To automatically set up a number of primarily luarocks-related environment variables:
```
./kodev activate
```
To run unit tests:
```
./kodev test base
./kodev test front
```
To run a specific unit test (for test development):
```
./kodev test front readerbookmark_spec.lua
```
To run Lua static analysis:
```
make static-check
```
NOTE: Extra dependencies for tests: `luacheck` from luarocks.
## Translations
Please refer to [l10n's README][l10n-readme] to grab the latest translations
Some strings contain variables that should remain unaltered in translation. These take the form of a `%` followed by a number from `1-99`, although you'll seldom see more than about 5 in practice. Please don't put any spaces between the `%` and its number. `%1` should always remain `%1`.
For example:
```lua
The title of the book is %1 and its author is %2.
```
This might be displayed as:
```lua
The title of the book is The Republic and its author is Plato.
```
To aid localization the variables may be freely positioned:
```lua
De auteur van het boek is %2 en de titel is %1.
```
That would result in:
```lua
De auteur van het boek is Plato en de titel is The Republic.
```
## Use ccache
Ccache can speed up recompilation by caching previous compilations and detecting
when the same compilation is being repeated. In other words, it will decrease
build time when the sources have been built before. Ccache support has been added to
KOReader's build system. To install ccache:
* in Ubuntu use:`sudo apt-get install ccache`
* in Fedora use:`sudo dnf install ccache`
* from source:
* download the latest ccache source from http://ccache.samba.org/download.html
* extract the source package in a directory
*`cd` to that directory and use:`./configure && make && sudo make install`
* to disable ccache, use `export USE_NO_CCACHE=1` before make.
* for more information about ccache, visit: https://ccache.samba.org/
