panic: lookupVers1, when standalone deriving Typeable and Data
When using !StandaloneDeriving and !DeriveDataTypeable on a rather large AST, occasionally GHC 6.8.2 and GHC 6.8.3 RC bail with
[13 of 24] Compiling Language.C.AST.Generic
...
ghc-6.8.2.20080527: panic! (the 'impossible' happened)
(GHC version 6.8.2.20080527 for i386-apple-darwin):
lookupVers1 language-c-test-0.2:Language.C.AST.Constants $cFlags{v}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
This is probably related to ticket #2011 (closed) (marked as milestone 6.8.3), clean and rebuild resolves the problem temporarily.
I haven't been able to extract a small test case, but the problematic source is available online at
http://code.haskell.org/language-c/src/Language/C/AST/Generic.hs
The bug is reproducible: (cabal) build, comment out the last 6 'deriving Data' clauses (line 96-101), build again, uncomment, build again.
Side notes: There is a warning (but no error !) when deriving a Typeable1 instance (maybe related to #1825 (closed))
[13 of 24] Compiling Language.C.AST.Generic
Var/Type length mismatch:
[f{tv i1lc} [tv]]
[]
... [as above]
Finally, in GHC 6.9 standalone deriving Data was unsupported as of 01042008:
[13 of 24] Compiling Language.C.AST.Generic
Illegal binding of built-in syntax: $cCHeader
Trac metadata
Trac field | Value |
---|---|
Version | 6.8.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | benedikt.huber@gmail.com |
Operating system | |
Architecture |