Exclude ext from binary gems

[glebm]

Not sure if this is the right repo for this feature request, but it'd be cool if rake-compiler automatically excluded the entire ext directory from gem files for precompiled gems.

[larskanis]

Could you please request this at the rake-compiler repository?

[glebm]

GitHub now supports moving issues to another repo!

https://help.github.com/en/articles/transferring-an-issue-to-another-repository

But I can't do it, only someone who is a maintainer of both repos can do it.

[larskanis]

Excluding files is already possible when making use of the cross_compiling block like here in nokogiri. Since it's so simple to exclude files but more difficult to re-add in case they are needed somehow, I'm not convinced that we should change it.

[glebm]

They shouldn't ever be needed, ext is only supposed to be used for compilation, and all the artefacts should go into lib (https://guides.rubygems.org/gems-with-extensions/).

Some OS package managers also delete the ext directory when packaging ruby gems as system packages (we had a related issue here sass/sassc-ruby#95).

Anyway, thanks for the tip, I hadn't realized it was that easy to exclude them!

Perhaps we could add removing ext to the example in the Readme, as this is the right thing to do most of the time, if not always?

[kou]

We can't determine what should we remove for extension perfectly.
For example:

• We may need to remove https://github.com/sparklemotion/nokogiri/tree/master/patches for Nokogiri case.
• We may need to remove https://github.com/sass/sassc-ruby/blob/master/lib/tasks/libsass.rb for sassc-ruby case.

So, adding some description to README is reasonable.
Could you create a pull request for this?