panic! (the 'impossible' happened) on ‘deriving instance lowercase_name a’
This bogus code:
{-# LANGUAGE StandaloneDeriving #-}
deriving instance lowercase_name acauses current GHC HEAD to panic:
ghc: panic! (the 'impossible' happened)
(GHC version 7.3.20110927 for x86_64-unknown-linux):
nameModule lowercase_name{tv aar}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabugI also tested GHC 7.0.3, which correctly diagnosed the problem:
crash.hs:2:19: Malformed instance header: lowercase_name aTrac metadata
| Trac field | Value |
|---|---|
| Version | 7.3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |