[GHC] #16095: Infinite loop during error reporting (ignores SIGINT/SIGTERM, then OOMs)

[GHC]

#16095: Infinite loop during error reporting (ignores SIGINT/SIGTERM, then OOMs)
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        Reporter:  _deepfire         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.6.1
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by _deepfire):

 When the `HasDatatypeInfo` constraint is removed, the error in the code
 can be printed:
 {{{
     Overlapping instances for C i0 a0
         arising from a use of ‘function’
       Matching instances:
         instance C i a -- Defined at doc/ghc-repro-16095.hs:15:10
         instance C i () -- Defined at doc/ghc-repro-16095.hs:13:10
       (The choice depends on the instantiation of ‘i0, a0’
        To pick the first instance above, use IncoherentInstances
        when compiling the other instance declarations)
     In the first argument of ‘undefined’, namely ‘function’
       In the expression: undefined function
       In an equation for ‘method’: method = undefined function
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16095#comment:3>
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