bingos/dist-zilla-plugin-assertos — pull request #2 by karenetheridge (2013-04-20 02:01:14+00:00)
Title: generate a fatal error if the plugin is run too soon, before Makefile.PL...

... or Build.PL can be generated for receiving the install-time OS-assertion code

(because I was a d00fus and spent a whole minute trying to figure out why it didn't work, before I went back and RTFMed) :)