@mikemcquaid Specifically, when the GCC branch lands the user can choose between any of the GNU GCCs they have installed (4.3 to 4.9), and `fails_with` will select any of them in order from newest to oldest. @darinmorrison is acting under the assumption that GHC won't build with any of them.

My preference would be to actually test with GNU GCCs before marking any as failing.