[GHC] #10052: Panic (something to do with floatExpr?)

[GHC]

#10052: Panic (something to do with floatExpr?)
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        Reporter:  edsko             |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.10.1-rc2
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
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Comment (by simonpj):

 Peter Wortman says: We are clearly trying to float past a breakpoint here,
 which is simply impossible. Pretty sure this would have been a panic
 before my changes too (it would have tried to "mkNoCount" the breakpoint).
 Guess I was wrong reading a "breakpoints don't appear here" invariant out
 of that...

 The quick fix would be to drop all floats in-place:
 {{{
     -- scoped, counting and unsplittable, can't be floated through
     | otherwise
     = floatBody tOP_LEVEL expr
 }}}
 This fixes the panic, but is a bit awkward. Probably better to change
 `SetLevels`? Not a piece of code I'm very familiar with...

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10052#comment:2>
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