GHC-7.6.1 panics on template haskell code
While experimenting with TH I stumbled upon a repeating compiler panic. After minifying I got this example which triggers the failure:
% cat Peekler.hs
module Peekler where
import Language.Haskell.TH
tst = do
o <- newName "Foo"
return $ [DataD [] o [] [RecC o []] [''Show]]
% cat PeeklerTest.hs
module PeeklerTest where
import Peekler
$(tst)
test = print Foo
% ghci -XTemplateHaskell PeeklerTest.hs
GHCi, version 7.6.1: http://www.haskell.org/ghc/ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
[1 of 2] Compiling Peekler ( Peekler.hs, interpreted )
[2 of 2] Compiling PeeklerTest ( PeeklerTest.hs, interpreted )
Loading package pretty-1.1.1.0 ... linking ... done.
Loading package array-0.4.0.1 ... linking ... done.
Loading package deepseq-1.3.0.1 ... linking ... done.
Loading package containers-0.5.0.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
ghc: panic! (the 'impossible' happened)
(GHC version 7.6.1 for i386-unknown-linux):
lookupExactOcc
<<details unavailable>>
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
>
Leaving GHCi.
% ghc -XTemplateHaskell PeeklerTest.hs
[1 of 2] Compiling Peekler ( Peekler.hs, Peekler.o )
[2 of 2] Compiling PeeklerTest ( PeeklerTest.hs, PeeklerTest.o )
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package pretty-1.1.1.0 ... linking ... done.
Loading package array-0.4.0.1 ... linking ... done.
Loading package deepseq-1.3.0.1 ... linking ... done.
Loading package containers-0.5.0.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
ghc: panic! (the 'impossible' happened)
(GHC version 7.6.1 for i386-unknown-linux):
lookupExactOcc
Foo_a18S{tc}
[main:PeeklerTest.Foo{tc a18S} defined at PeeklerTest.hs:5:3,
main:PeeklerTest.Foo{d a18S} defined at PeeklerTest.hs:5:3]
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
% lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.04.1 LTS
Release: 12.04
Codename: precise
Trac metadata
Trac field | Value |
---|---|
Version | 7.6.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |