activesupport needs the symbol TZInfo. tzinfo is a dependent of active record so rails server won't start without it.
That's just great. Gotta love the Rails guys. I once filed a bug report saying that AR has a dependency on tzinfo while activesupport didn't. The issue was fixed by moving the dependency.
They must've changed it back in some recent release.
Any way we can add a test for this?
Well - the pull request only involves documentation.
(I guess it would be possible to have a test that makes sure that the suggested gems for rails interop works as intended. But then we would have two lists of gems to maintain. Unless we want to insert the list into the documentation automatically. No idea how that would work.)
Oops, sorry. I thought you had touched the Gemfile.