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  • #12957

Closed
Open
Opened Dec 09, 2016 by niteria@trac-niteria

In a record-update construct:ghc-stage2: panic! (the 'impossible' happened)

While compiling Repro.hs with HEAD I get this:

$ ~/local/ghc-inaccessible-right-side/inplace/bin/ghc-stage2 Repro.hs
[1 of 1] Compiling Repro            ( Repro.hs, Repro.o )

Repro.hs:22:35: warning: [-Woverlapping-patterns]
    Pattern match has inaccessible right hand side
    In a record-update construct:ghc-stage2: panic! (the 'impossible' happened)
  (GHC version 8.1.20161209 for x86_64-unknown-linux):
        unused

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

It doesn't reproduce on 7.10.2. I'm 90% sure it reproduces on 8.0.2 (I have a branch with some unrelated patches).

Trac metadata
Trac field Value
Version
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture
Assignee
Assign to
8.2.1
Milestone
8.2.1 (Past due)
Assign milestone
Time tracking
None
Due date
None
Reference: ghc/ghc#12957