[GHC] #10896: BadSock triggers failing ASSERT

[GHC]

#10896: BadSock triggers failing ASSERT
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        Reporter:  ezyang            |                   Owner:
            Type:  bug               |                  Status:  patch
        Priority:  normal            |               Milestone:
       Component:  Compiler (Type    |                 Version:  7.11
  checker)                           |
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:  Phab:D1260
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Comment (by Richard Eisenberg <eir@…>):

 In [changeset:"8e8b9ed9849ba21e454e6204b368f8e993feaf7b/ghc" 8e8b9ed/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="8e8b9ed9849ba21e454e6204b368f8e993feaf7b"
 Run simplifier only when the env is clean.

 This fixes #10896. In the indexed-types/should_fail/BadSock test,
 there is a bad type definition. This gets type-checked, an error
 gets reported, but then **GHC keeps going**. Later, when
 running the simplifier to do an ambiguity check, the bad type
 environment causes GHC to fall over. My solution: only run the
 simplifier in a clean, error-free type environment.

 A downside of this is that fewer error messages are reported.
 This makes me a bit sad, but I'm not sure how to avoid the problem.
 Suggestions welcome.
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10896#comment:3>
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