ghc: panic! (the 'impossible' happened)

• *Command**

ghc -c prettystub.hs

• *Result**

ghc: panic! (the 'impossible' happened)
  (GHC version 8.0.2 for x86_64-unknown-mingw32):
        initTc: unsolved constraints
  WC {wc_insol =
        [W] hexEscape_a2yj :: t_a2yi[tau:1] (CHoleCan: hexEscape)}

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Trac metadata

Trac field	Value
Version	8.0.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

changed weight to 5

added Tbug Trac import labels

Attached file PrettyJSON.hs ($1276).

source file to be compiled

Attached file PrettyStub.hs ($1277).

required module #1 (closed)

Perhaps a dup of #13416 (closed)?

Attached file SimpleJSON.hs ($1278).

required module #2 (closed)

closed

Replying to [ticket:13432#comment:133592 simonpj]:

Perhaps a dup of #13416 (closed)?

Yep. You'll get a better error message in GHC 8.2:

[1 of 3] Compiling SimpleJSON       ( SimpleJSON.hs, interpreted )
[2 of 3] Compiling PrettyStub       ( PrettyStub.hs, interpreted )
[3 of 3] Compiling Main             ( PrettyJSON.hs, interpreted )

PrettyJSON.hs:23:36: error:
    Variable not in scope: hexEscape :: Char -> Doc
   |
23 |         Nothing | mustEscape c  -> hexEscape c
   |

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedDuplicate
Related	- → #13416 (closed)

added compiler crash label

added Pnormal label