Ignoring GEM because its extensions are not built

Question

On both my work and home computers, I recently upgraded Ruby to 2.3.1, using ruby-install. I use chruby as my Ruby switcher.

I started seei

Answer 1

TL;DR - Ruby gems don't like Rubies running from symlinks or moved from where they were built (because of embedded shebangs)

If the Ruby directory is invoked or environment vars point to a symlink'ed directory, or are copied or renamed, this message is likely. I am using chruby and was symlinking /opt/rubies/ -> /usr/local/ruby/, but Ruby's dynamic library-finding logic doesn't play well with this.

The solution in my case was to replace the symlink with actual rubies in /opt/rubies/ and run gem pristine --all in each Ruby. For others using RVM or Rbenv, good luck with that without starting over from scratch.

This may not be your exact issue, but hopefully it helps.