Oh I forgot to mention that I was testing on my local branch which fixes precisely this kind of bug when the CallStack is used inside a let-binder, which is what happens in rewriteEqEvidence.
So it looks like my patch takes care of this issue. Thanks for the report! Sent from my iPhone > On Dec 7, 2015, at 11:25, Richard Eisenberg <e...@cis.upenn.edu> wrote: > > >> On Dec 7, 2015, at 2:23 PM, Eric Seidel <e...@seidel.io> wrote: >> >> After staring at your bug confusedly for a few minutes, wondering why I >> couldn't simplify it, I realized that the actual warning I was getting >> was in *mkTcTransCo*, not rewriteEqEvidence. mkTcTransCo does not in >> fact use a CallStack (by default) so the redundant constraint warning >> there would be correct. If I add a call to error, everything seems to >> check out. >> >> Can you confirm? > > No. I had modified mkTcTransCo to print out the call-stack, so that wasn't > the problem. If you can't reproduce quickly, I'll take another look at this > when I get a chance. Thanks for taking a pass. > > Richard > >> >> Thanks! >> Eric > _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
