bad error message when parsing fails due to fixity resulution

[int-e]

Consider the following interaction with pointfree, which spouts an error about Template Haskell seemingly out of the blue.

# pointfree 'a . b ? c'
TemplateHaskell language extension is not enabled. Please add {-# LANGUAGE TemplateHaskell #-} pragma at the top of your module.

It turns out that this results from pointfree parsing the input as a declaration if parsing it as an expression fails, because any expression can be parsed as a bare top-level template splice.

Prelude Language.Haskell.Exts> parseExp "a . b ? c"
ParseFailed (SrcLoc "" -1 -1) "Ambiguous infix expression"

Prelude Language.Haskell.Exts> parseDecl "a . b ? c"
ParseFailed (SrcLoc "<unknown>.hs" 1 10) "TemplateHaskell language extension is not enabled. Please add {-# LANGUAGE TemplateHaskell #-} pragma at the top of your module."

Maybe pointfree should print both errors when parsing fails, for example:

# pointfree 'a . b ? c'
parsing as an expression failed with "Ambiguous infix expression"
parsing as a declaration failed with "TemplateHaskell language extension is not enabled. Please add {-# LANGUAGE TemplateHaskell #-} pragma at the top of your module."