#10789

[sasa bogicevic]

Hello,
I am looking at this task https://ghc.haskell.org/trac/ghc/ticket/10789 <https://ghc.haskell.org/trac/ghc/ticket/10789> and need some help on implementing it.
With the help of @int_index I found the place in TcErrors.hs where the error printing occurs  and I think the check
that I need to add will look similar to this one https://github.com/ghc/ghc/blob/master/compiler/typecheck/TcErrors.hs#L1935 <https://github.com/ghc/ghc/blob/master/compiler/typecheck/TcErrors.hs#L1935>.

So I guess that we need to check if one of the kinds of two types we are comparing defaults to * (or  Type if you will) and then
add new warning that will be more descriptive as to why the failure happened. Maybe there is a way to check if what we are
comparing are actually type families so that would make the job easier I guess.

Richard Eisenberg offered some help on this but I am not sure how to grab hold of him so I'd appreciate any help I could get.

Thanks, Sasa



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