Opened 9 years ago

Closed 9 years ago

Last modified 9 years ago

#2011 closed merge (fixed)

[6.8.1 regression] panic: lookupVers1 base:GHC.Prim sym{tc}

Reported by: simonmar Owned by: igloo
Priority: high Milestone: 6.8.3
Component: Compiler Version: 6.8.2
Keywords: Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: None/Unknown Test Case:
Blocked By: Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:


When rebuilding the base package you might encounter this:

../../compiler/stage1/ghc-inplace -package-name base- -hide-all-packages -split-objs -i -idist/build/autogen -idist/build -i. -Idist/build -Iinclude -#include "HsBase.h" -odir dist/build -hidir dist/build -stubdir dist/build -package rts-1.0 -O -fglasgow-exts -package-name base -XCPP -idist/build  -H16m -O -O -Rghc-timing -fgenerics -c Data/Generics/Twins.hs -o dist/build/Data/Generics/Twins.o  -ohi dist/build/Data/Generics/Twins.hi
ghc-6.8.2: panic! (the 'impossible' happened)
  (GHC version 6.8.2 for powerpc-apple-darwin):
        lookupVers1 base:GHC.Prim sym{tc}

Workaround is to clean in libraries/base.

The problem is that MkIface.computeChangedOccs needs to avoid wired-in names when checking version numbers, because wired-in names are never mentioned in usages.

I believe simonpj has a patch for this in his working tree, we diagnosed it before disappearing for the Christmas period.

Change History (4)

comment:1 Changed 9 years ago by simonpj

Owner: changed from simonpj to igloo
Type: bugmerge

The patch is this one. Ian, please merge to 6.8 branch.

Thu Dec 20 16:43:07 GMT 2007
  * Fix nasty recompilation bug in MkIface.computeChangedOccs
  	MERGE to 6.8 branch
  In computeChangedOccs we look up the old version of a Name.
  But a WiredIn Name doesn't have an old version, because WiredIn things
  don't appear in interface files at all.
  Result: ghc-6.9: panic! (the 'impossible' happened)
    (GHC version 6.9 for x86_64-unknown-linux):
  	lookupVers1 base:GHC.Prim chr#{v}
  This fixes the problem.  The patch should merge easily onto the branch.

comment:2 Changed 9 years ago by igloo

Resolution: fixed
Status: newclosed


comment:3 Changed 9 years ago by simonmar

Architecture: UnknownUnknown/Multiple

comment:4 Changed 9 years ago by simonmar

Operating System: UnknownUnknown/Multiple
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