initTc: unsolved constraints

While working on a small project of mine, GHC panicked with the following error:

lua-types-0.1.0.0: build
Preprocessing executable 'lua-types' for lua-types-0.1.0.0...
[2 of 3] Compiling Lua.Parser       ( src/Lua/Parser.hs, .stack-work/dist/x86_64-osx/Cabal-1.24.1.0/build/lua-types/lua-types-tmp/Lua/Parser.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 8.0.1.20161117 for x86_64-apple-darwin):
	initTc: unsolved constraints
  WC {wc_insol =
        [W] explist_a3nf :: t_a3ne[tau:1] (CHoleCan: explist)
        [W] funccall_a4dv :: t_a4du[tau:1] (CHoleCan: funccall)}

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

From a quick google search, it seems like this is a bug in the type checker. I'm not willing nor able to dive any further into the GHC code myself, though.

I'll attach the code as it is, before looking for a workaround. I'm using stack, GHC version 8.0.1.20161117 for x86_64-apple-darwin.

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (Type checker)
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