vim - macOS Mojave 'ruby/config.h' file not found

Question

When I try to build vim(8.1.0509) with ruby support(--enable-rubyinterp) on macOS Mojave(10.14.1) I get error:

In file included from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/include/ruby-2.3.0/ruby.h:33:
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/include/ruby-2.3.0/ruby/ruby.h:24:10: fatal error:
      'ruby/config.h' file not found
#include "ruby/config.h"

I have installed Xcode 10.1.

xcode-select -p
/Applications/Xcode.app/Contents/Developer

Thanks

Answer 1

macOS Catalina

Issue reappeared in Catalina and I wasn't able to spot this package in the Developer SDK. Until better solution found, I was able to workaround this with rubyenv: https://github.com/orta/cocoapods-keys/issues/198#issuecomment-510909030

brew install rbenv ruby-build
echo 'if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi' >> ~/.bash_profile 
rbenv install 2.6.3
rbenv global 2.6.3

Mojave and older

This answer helped me: https://stackoverflow.com/a/53194299/2105993

xcode-select --install
open /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg