Assertion failed with BuildFlavour = devel2 (one more)
Affected versions: ghc 8.0.1 and ghc git master as of 21 Oct 2016 (c23dc616)
It compiles fine on first time but fails to compile on second attempt. Using -fforce-recomp recompiles both files and bug is not triggered.
% ls
A.hs B.hs
% cat A.hs
module A where
import B
foo a = case a of
Foo -> True
_ -> False
% cat B.hs
{-# LANGUAGE PatternSynonyms, ScopedTypeVariables #-}
module B where
pattern Foo = 0x00000001 :: Int
% ghc -O2 A.hs ; touch A.hs ; ghc -O2 A.hs
[1 of 2] Compiling B ( B.hs, B.o )
[2 of 2] Compiling A ( A.hs, A.o )
[2 of 2] Compiling A ( A.hs, A.o )
ghc: panic! (the 'impossible' happened)
(GHC version 8.0.1 for x86_64-unknown-linux):
ASSERT failed!
CallStack (from HasCallStack):
assertPprPanic, called at compiler/iface/BuildTyCl.hs:195:404 in ghc:BuildTyCl
[] ~ []
[] ~ []
Int ~ Int
[] ~ []
[] ~ []
[] ~ [Void#]
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |