Hi Simon, I'm seeing some rather peculiar validation issues with your most recent patch. Namely, =====> T13156(normal) 1 of 1 [0, 0, 0] cd "./simplCore/should_compile/T13156.run" && $MAKE -s --no-print-directory T13156 Actual stdout output differs from expected: diff -uw "./simplCore/should_compile/T13156.run/T13156.stdout.normalised" "./simplCore/should_compile/T13156.run/T13156.run.stdout.normalised" --- ./simplCore/should_compile/T13156.run/T13156.stdout.normalised 2017-01-20 13:00:46.620654541 -0500 +++ ./simplCore/should_compile/T13156.run/T13156.run.stdout.normalised 2017-01-20 13:00:46.620654541 -0500 @@ -1,5 +1,2 @@ case GHC.List.reverse @ a x of sat { __DEFAULT -> - case \ (@ a) -> - case g x of { - case r @ GHC.Types.Any of { __DEFAULT -> - case r @ GHC.Types.Any of { __DEFAULT -> GHC.Types.True } + case case g x of { Oddly enough Harbormaster isn't reproducing this, but it seems to be quite reproducible locally. Do you have any idea what might be going on here? Cheers, - Ben