First off, thank you to David Landgren for remembering that Perlmonks is not the Test::More bug tracker and thinking to mention this issue to me. Bitching on Perlmonks might get you a work around, but it won't fix the underlying problem. The bug tracker is here:
This concludes my quasi-annual bitching at Perlmonks.
The issue at hand appears to be that MakeMaker only added manual glob expansion of tests in 6.27. I can't pre-expand them in the Makefile.PL else it will blow out the shell exec length limit on some platforms. In theory, I could have Test::More depend on MakeMaker 6.27 since there's no circularity. I'm not sure.
Anyhow, somebody report the bug.