ghc-HEAD -DDEBUG is broken (possiby by D1880)

Was found when tried to build with

BuildFlavour = devel2

ghc-validate $ LANG=C make V=0

  HC [stage 2] libraries/parallel/dist-install/build/Control/Seq.o
WARNING: file compiler/stgSyn/CoreToStg.hs, line 250
  using False True
ghc-stage2: panic! (the 'impossible' happened)
  (GHC version 8.1.20160206 for x86_64-unknown-linux):
        ASSERT failed!
  CallStack (from HasCallStack):
  assertPprPanic, called at compiler/stgSyn/CoreToStg.hs:216:59 in ghc:CoreToStg
  using

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

https://travis-ci.org/ghc/ghc/builds

suggests

changeset:4f9967aa

might be at fault.

Reverting it on top of master fixes devel2 build.

Trac metadata

Trac field	Value
Version	8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	osa1, skvadrik
Operating system
Architecture