Alter default bundled gems

[gouravkhunger]

Describe the problem as clearly as you can

I am working on a native android application that runs ruby and gem using a Termux like environment but targeting android 10+. A demo release can be found here.

Targeting android 10 and above for an android app requires all the necessary executables to be bundled into the app which means even though I can run ruby, gem and the default bundled gems on the app with no issues, I can gem install xyz successfully but cannot expect to run any executables that came through xyz.

For example, I can gem install jekyll by having the required build tools (make, clang, etc.). Installation would work but the jekyll executable won't work because Android 10 and above won't let externally loaded binaries execute.

To be precise: I want to know how to alter the default set of bundled gems that come through rubygems into my ruby build.

Or maybe please direct me how .gem files work. I could maybe also pre-expand the .gem files to include them into my environment bootstrap zip file so as to include those executable when the apk installs. For gems like nokogiri, I can precompile the required extensions.

Please let me know if this needs more clarity. Thanks!

[gouravkhunger]

Adding this for someone else tinkering with compiling ruby from source.

The bundled gems are listed in the bundler_gems plain text file at ruby's source. I was successfully able to patch the file and see the additional gems get bundled.

If the target OS is different, it might be required to patch the sources of the additional gems listed (if they contain native extensions) so that they become compatible for the target OS. rbinstall.rb can be altered to apply such patches just before the gems is going to be prepared to be bundled. Here's an example.