Apparently, some of rspec-core's own specs fail on Fedora:
https://github.com/rspec/rspec-core/issues/662
It's puzzling, since they pass for me on OS X and also on travis-ci,
which runs Ubuntu. I'd like to see this fixed, but I don't have a
Fedora environment available. I don't think any of the other rspec
core contributors do, either.
So...if you use Fedora and are up for helping out, please stop by on
that ticket and lend a hand :).
Thanks,
Myron