the 'impossible' happened : expectJust block_order

Currently at commit 7e91e5bf and this was not failing to build 2 days ago.

Compiling results in:

"inplace/bin/ghc-stage1" -hisuf dyn_hi -osuf  dyn_o -hcsuf dyn_hc -fPIC -dynamic 
  -H32m -O -Werror -Wall -H64m -O0    -hide-all-packages -i -iutils/hpc/. 
  -iutils/hpc/dist-install/build -iutils/hpc/dist-install/build/autogen
  -Iutils/hpc/dist-install/build -Iutils/hpc/dist-install/build/autogen
  -optP-include -optPutils/hpc/dist-install/build/autogen/cabal_macros.h
  -package array-0.4.0.2 -package base-4.7.0.0 -package containers-0.5.2.1
  -package directory-1.2.0.1 -package hpc-0.6.0.1 -XHaskell98 -XCPP
  -no-user-package-db -rtsopts -fwarn-tabs     -odir utils/hpc/dist-install/build
  -hidir utils/hpc/dist-install/build -stubdir utils/hpc/dist-install/build
  -c utils/hpc/dist-install/build/HpcParser.hs
  -o utils/hpc/dist-install/build/HpcParser.dyn_o 
ghc-stage1: panic! (the 'impossible' happened)
  (GHC version 7.7.20130830 for powerpc64-unknown-linux):
        expectJust block_order

Trac metadata

Trac field	Value
Version	7.7
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Linux
Architecture	powerpc64