[GHC] #11525: Using a dummy typechecker plugin causes an ambiguity check error

[GHC]

#11525: Using a dummy typechecker plugin causes an ambiguity check error
-------------------------------------+-------------------------------------
        Reporter:  jme               |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.2.1
       Component:  Compiler (Type    |              Version:  8.0.1-rc1
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by darchon):

 * milestone:   => 8.2.1


Comment:

 As I (`christiaanb` on IRC) have several type-checker plugins released on
 Hackage, I would like to see a fix for this included in the GHC 8.2.1
 release. I've already asked Adam Gundry for some guidance in helping me
 fix it. Although I surely wouldn't mind if someone with more familiarity
 with the affected part of the codebase could work out a fix for this bug
 instead ;-)

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11525#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler