unregisterised GHC fails buid as: ghc-stage1: panic! (the 'impossible' happened): pprCLbl AsmTempLabel

How to repdoruce on amd64:

$ ./configure --enable-unregisterised
$ make

Build failure:

  rts_dist_HC rts/dist/build/PrimOps.o
ghc-stage1: panic! (the 'impossible' happened)
  (GHC version 8.3.20170920 for x86_64-unknown-linux):
ghc-stage1: panic! (the 'impossible' happened)
  (GHC version 8.3.20170920 for x86_64-unknown-linux):
        ghc-stage1: panic! (the 'impossible' happened)
  (GHC version 8.3.20170920 for x86_64-unknown-linux):
        pprCLbl AsmTempLabel

Normally UNREG backend has no asm labels.

changeset:8b007abb looks vaguely relevant as it adds AsmTempLabel in one place. But I did not look in detail yet.

Trac metadata

Trac field	Value
Version	8.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	bgamari
Operating system
Architecture