RecordWildCards panic
GHC 7.4.1 (Debian 7.7 and Ubuntu 12.04.5 LTS) panics with:
ghc: panic! (the 'impossible' happened)
(GHC version 7.4.1 for i386-unknown-linux):
compiler/rename/RnPat.lhs:535:39-79: Irrefutable pattern failed for pattern gres@(gre : _)
I found a minimal test case to exemplify this issue:
module Foo where
import Bar (Bar (Bar))
foo :: Bar -> ()
foo Bar {..} = ()
module Bar where
data Bar = Bar { barA :: Int, barB :: Int }
A workaround is to import all data fields in module Foo:
import Bar (Bar (..))
I also tried this with GHC 7.6.3 (Mac OS X), with no warnings nor errors.
Trac metadata
Trac field | Value |
---|---|
Version | 7.4.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |