I'm trying to install the gem 'taglib-ruby' on Heroku. This gem compiles as a native extension which requires a system dependency called taglib, so after compiling and uploading it through heroku vulcan, I achieved to compile the gem via command line on heroku bash:
bundle exec gem install taglib-ruby -- --with-opt-dir=/app/vendor/taglib
And in order to this parameter would be used by bundler later, I added it as a bundler configuration through the command:
bundle config build.taglib-ruby '--with-opt-dir=/app/vendor/taglib'
I've already verified this config was applied, inspecting the file /.bundle/config and looking for the line BUNDLE_BUILD__TAGLIB-RUBY.
However after pushing out my project to heroku and while it is executing the bundle install command, heroku complains that the above gem (taglib-ruby) cannot be installed due the taglib library isn't present, although it's what I was trying to solve with the option '--with-opt-dir=/app/vendor/taglib' mentioned above.
So it appears that Heroku is ignoring the bundler configuration.
What could be happening? Do you know another way the achieve the same intention (install a gem with custom build options) on Heroku?