Check that GHC.Real compiles without OPTIMISE_INTEGER_GCD_LCM nor MIN_VERSION_integer_gmp defined.
I know... my point (which I should have made more explicit) was rather that re-wrapping import lists in this way (rather than keeping this a single-line modification) is bad practice for patches, as it's hard to review, makes the output of git blame less useful, and significantly increases the risk of merge conflicts.
master just got this commit:
commit 633814f5664f135b3648e2a0a6f37e41e2b54ea0 Author: Joachim Breitner <email@example.com> Date: Sat Jan 3 14:39:52 2015 +0100 Mark T9938 as not broken either one of the two recent commits (d8d0031, fd97d2a) fixed it, or there is some nondeterminism here. See #9938.
So thankfully nothing to do with me!