[GHC] #8569: ASSERT in testcase type-rep, only in some ways:

[GHC]

#8569: ASSERT in testcase type-rep, only in some ways:
-------------------------------------+------------------------------------
        Reporter:  nomeata           |            Owner:
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Test Suite        |          Version:  7.7
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
-------------------------------------+------------------------------------
Changes (by simonpj):

 * status:  closed => new
 * resolution:  wontfix =>


Comment:

 I’m seeing this assertion failure when using the stage1 compiler (built
 with –DDEBUG) to compile the stage2 compiler.
 {{{
 ghc-stage1.exe: panic! (the 'impossible' happened)
   (GHC version 7.9.20140227 for i386-unknown-mingw32):
           ASSERT failed!
     file compiler\basicTypes\Demand.lhs line 445
     3
     [U]
 }}}
 Turns out that it's another instance of this ticket, but now the bug is
 now biting GHC itself!  However the `type-rep` test is a much easier
 version to debug.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8569#comment:12>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler