[commit: ghc] wip/T9858-typeable-ben: Motre debug (3692051)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/T9858-typeable-ben
Link       : http://ghc.haskell.org/trac/ghc/changeset/3692051741066f6de2b714e397d1f6b7097c2810/ghc

>---------------------------------------------------------------

commit 3692051741066f6de2b714e397d1f6b7097c2810
Author: Ben Gamari <ben at smart-cactus.org>
Date:   Wed Oct 28 11:42:31 2015 +0100

    Motre debug


>---------------------------------------------------------------

3692051741066f6de2b714e397d1f6b7097c2810
 compiler/types/Unify.hs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/compiler/types/Unify.hs b/compiler/types/Unify.hs
index 2ee3758..f4e7b37 100644
--- a/compiler/types/Unify.hs
+++ b/compiler/types/Unify.hs
@@ -577,7 +577,9 @@ unify ty1 ty2
   = if tc1 == tc2
     then if isInjectiveTyCon tc1 Nominal
          then unify_tys tys1 tys2
-         else pprTrace "NotSoFast" (hsep [ppr tc1, ppr tys1, ppr tc2, ppr tys2]) $ don'tBeSoSure $ unify_tys tys1 tys2
+         else do tmp <- runUM (unify_tys tys1 tys2)
+                 don'tBeSoSure $ pprTrace "NotSoFast" (hsep [ppr tc1, ppr tys1, ppr tc2, ppr tys2, ppr tmp]) 
+                               $ unify_tys tys1 tys2
     else -- tc1 /= tc2
          if isGenerativeTyCon tc1 Nominal && isGenerativeTyCon tc2 Nominal
          then surelyApart