Gem Spec support for git submodules inside a gem.

gem-with-git-submodules.gemspec

Gem::Specification.new do |s|
  # normal spec stuff above
  s.files = `git ls-files`.split("\n")

  # get an array of submodule dirs by executing 'pwd' inside each submodule
  gem_dir = File.expand_path(File.dirname(__FILE__)) + "/"
  `git submodule --quiet foreach pwd`.split($\).each do |submodule_path|
    Dir.chdir(submodule_path) do
      submodule_relative_path = submodule_path.sub gem_dir, ""
      # issue git ls-files in submodule's directory and
      # prepend the submodule path to create absolute file paths
      `git ls-files`.split($\).each do |filename|
        s.files << "#{submodule_relative_path}/#{filename}"
      end
    end
  end
end

Hey, thanks for your optimizations. I will update the post with a link to this gist.

I updated the post.

Using Pathname:

`git submodule --quiet foreach pwd`.split($\).each do |submodule_path|
  Dir.chdir(submodule_path) do
    relative = Pathname.new(submodule_path).relative_path_from(__dir__)
    `git ls-files`.split($\).each do |filename|
      spec.files << relative.join(filename).to_s
    end
  end
end