[GHC] #14148: initTc: unsolved constraints

[GHC]

#14148: initTc: unsolved constraints
----------------------------------+--------------------------------------
        Reporter:  robertpergl    |                Owner:  (none)
            Type:  bug            |               Status:  closed
        Priority:  normal         |            Milestone:
       Component:  Compiler       |              Version:  8.0.2
      Resolution:  duplicate      |             Keywords:
Operating System:  Linux          |         Architecture:  x86_64 (amd64)
 Type of failure:  Runtime crash  |            Test Case:
      Blocked By:                 |             Blocking:
 Related Tickets:  #13106         |  Differential Rev(s):
       Wiki Page:                 |
----------------------------------+--------------------------------------
Changes (by RyanGlScott):

 * status:  new => closed
 * resolution:   => duplicate
 * related:   => #13106


Old description:

> || ghc: panic! (the 'impossible' happened)
> ||   (GHC version 8.0.2 for x86_64-unknown-linux):
> ||      initTc: unsolved constraints
> ||   WC {wc_insol =
> ||         [W] ltail_ae2e :: t_ae2d[tau:1] (CHoleCan: ltail)
> ||         [W] lhead_ae2h :: t_ae2g[tau:1] (CHoleCan: lhead)}

New description:

 {{{
 ghc: panic! (the 'impossible' happened)
   (GHC version 8.0.2 for x86_64-unknown-linux):
         initTc: unsolved constraints
   WC {wc_insol =
         [W] ltail_ae2e :: t_ae2d[tau:1] (CHoleCan: ltail)
         [W] lhead_ae2h :: t_ae2g[tau:1] (CHoleCan: lhead)}
 }}}

--

Comment:

 Thanks for the bug report. This is a duplicate of #13106, which has been
 fixed in GHC 8.2.1. In 8.2.1, I get this error message instead:

 {{{
 [3 of 4] Compiling Rendering        ( app/Rendering.hs,
 dist/build/HOntoUML/HOntoUML-tmp/Rendering.o )

 app/Rendering.hs:110:132: error:
     • Variable not in scope: ltail :: Text
     • Perhaps you meant ‘tail’ (imported from Prelude)
     |
 110 |   renderClippedEdge i1 i2 [textLabel $ mLabel2Label mLbl, HeadLabel
 (StrLabel m2), TailLabel (StrLabel m1), arrowTo noArrow, LTail ltail,
 LHead lhead]
     |
 ^^^^^

 app/Rendering.hs:110:145: error:
     • Variable not in scope: lhead :: Text
     • Perhaps you meant ‘head’ (imported from Prelude)
     |
 110 |   renderClippedEdge i1 i2 [textLabel $ mLabel2Label mLbl, HeadLabel
 (StrLabel m2), TailLabel (StrLabel m1), arrowTo noArrow, LTail ltail,
 LHead lhead]
     |
 ^^^^^

 app/Rendering.hs:113:40: error:
     • The constructor ‘OUAssocPHInst’ should have 1 argument, but has been
 given 3
     • In the pattern: OUAssocPHInst mLbl (i1, m1) (i2, m2)
       In an equation for ‘renderAssocPHInst’:
           renderAssocPHInst
             ouModel
             ouModelInst
             (OUAssocPHInst mLbl (i1, m1) (i2, m2))
             = renderClippedEdge
                 i1
                 i2
                 [textLabel (ouphMetaLabel phMeta),
                  TailLabel (StrLabel $ m1 <> "<" <> aggregType <> ">"),
                  HeadLabel (StrLabel m2), ....]
     |
 113 | renderAssocPHInst ouModel ouModelInst (OUAssocPHInst mLbl (i1, m1)
 (i2, m2)) =
     |
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14148#comment:2>
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