Here's what I get, on a clean validate. =====> T9939(normal) 2555 of 4389 [0, 0, 0] cd ./typecheck/should_compile && '/home/hs01/ezyang/ghc-validate/inplace/bin/ghc-stage2' -fforc e-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-warn-tabs - fno-ghci-history -c T9939.hs -fno-warn-incomplete-patterns >T9939.comp.stderr 2>&1 Actual stderr output differs from expected: --- ./typecheck/should_compile/T9939.stderr 2015-01-06 13:51:47.089376284 -0800 +++ ./typecheck/should_compile/T9939.comp.stderr 2015-01-06 15:24:39.923007911 -0800 @@ -1 +1,18 @@ \ No newline at end of file +T9939.hs:5:7: + Redundant constraint: Eq a + In the type signature for: f1 :: (Eq a, Ord a) => a -> a -> Bool + +T9939.hs:9:7: + Redundant constraint: Eq a + In the type signature for: f2 :: (Eq a, Ord a) => a -> a -> Bool + +T9939.hs:13:7: + Redundant constraint: Eq b + In the type signature for: + f3 :: (Eq a, a ~ b, Eq b) => a -> b -> Bool + +T9939.hs:20:7: + Redundant constraint: Eq b + In the type signature for: + f4 :: (Eq a, Eq b) => a -> b -> Equal a b -> Bool *** unexpected failure for T9939(normal) =====> T9938(normal) 3401 of 4389 [0, 1, 0] cd ./driver && $MAKE -s --no-print-directory T9938 T9938.run.stdout 2>T9938.run. stderr Wrong exit code (expected 0 , actual 2 ) Stdout: Makefile:592: recipe for target 'T9938' failed Stderr: T9938.o: In function `r3Ho_info': (.text+0x52): undefined reference to `transzuH9c1w14lEUN3zzdWCTsn8jG_ControlziMonadziTransziSta teziLazzy_zdwzdcp1Alternative_info' collect2: error: ld returned 1 exit status make[3]: *** [T9938] Error 1 *** unexpected failure for T9938(normal) Edward