* you validate locally (in a different build directory, so you can keep using build flavour = devel2 in your development directory)

* fork the ghc github repository, push your branch there, and let Travis validate it: https://ghc.haskell.org/trac/ghc/wiki/TestingPatches#Travis

 

* ask Austin for some special Phabricator syntax that you could add when you submit the patch, to request Harbormaster not to rebase onto HEAD before validating