[commit: ghc] master: Re-add accidentally-deleted line (3adaacd)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/3adaacde6b8ad6f41e1554598a9fd93d9e605bc2/ghc

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

commit 3adaacde6b8ad6f41e1554598a9fd93d9e605bc2
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Mon Oct 17 09:23:50 2016 +0100

    Re-add accidentally-deleted line
    
    This adds a line I deleted by mistake in
    
      commit db71d971379c74dd1d2b958c11dc6c9e718a3e61
      Author: Simon Peyton Jones <simonpj at microsoft.com>
      Date:   Fri Oct 14 17:40:51 2016 +0100
    
          Reduce trace output slightly
    
    Sorry about that!


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

3adaacde6b8ad6f41e1554598a9fd93d9e605bc2
 compiler/typecheck/TcSMonad.hs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/typecheck/TcSMonad.hs b/compiler/typecheck/TcSMonad.hs
index fa4b169..37740bd 100644
--- a/compiler/typecheck/TcSMonad.hs
+++ b/compiler/typecheck/TcSMonad.hs
@@ -3107,7 +3107,8 @@ matchFam tycon args = wrapTcS $ matchFamTcM tycon args
 matchFamTcM :: TyCon -> [Type] -> TcM (Maybe (Coercion, TcType))
 -- Given (F tys) return (ty, co), where co :: F tys ~ ty
 matchFamTcM tycon args
-  = do { let match_fam_result
+  = do { fam_envs <- FamInst.tcGetFamInstEnvs
+       ; let match_fam_result
               = reduceTyFamApp_maybe fam_envs Nominal tycon args
        ; TcM.traceTc "matchFamTcM" $
          vcat [ text "Matching:" <+> ppr (mkTyConApp tycon args)