UnliftedNewtypesDifficultUnification broken due to simplified subsumption
UnliftedNewtypesDifficultUnification fails due to simplified subsumption patch (!2600 (merged)) in DEBUG-enabled compiler.
Compile failed (exit code 1) errors were:
ghc-stage2: panic! (the 'impossible' happened)
(GHC version 8.11.0.20200603:
ASSERT failed! file compiler/GHC/Core/FamInstEnv.hs, line 651
Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug
*** unexpected failure for UnliftedNewtypesDifficultUnification(normal)I have marked this test as broken in the interest of getting !2600 (merged) merged.
As seen in Job #356282.