You can clone with
HTTPS or Subversion.
Running specs in the gem version of yard causes failure because a number of specs expect to be able to read yard.gemspec and work from there. Running specs from a github tarball works as expected.
We should probably include the .gemspec in the .gem, that would solve this.
Yes, plenty of other gems do that as well. For Gentoo we now install from the github tarball which is fine with me, so I don't have a strong preference.
Package the gemspec file in the gem for tests.
Yo dawg, I heard you like testing so I put a gemspec in your gemspec
so you can test the gem while you gem install.