Ticket #7117: ghci-data-family.diff

File ghci-data-family.diff, 611 bytes (added by parcs, 3 years ago)

Potential fix

  • compiler/typecheck/TcInstDcls.lhs

    diff --git a/compiler/typecheck/TcInstDcls.lhs b/compiler/typecheck/TcInstDcls.lhs
    index 64f961c..af52c42 100644
    a b addFamInsts :: [FamInst] -> TcM a -> TcM a 
    432432--        (b) the type envt with stuff from data type decls 
    433433addFamInsts fam_insts thing_inside 
    434434  = tcExtendLocalFamInstEnv fam_insts $  
    435     tcExtendGlobalEnvImplicit things  $  
     435    tcExtendGlobalEnv things $ 
    436436    do { traceTc "addFamInsts" (pprFamInsts fam_insts) 
    437437       ; tcg_env <- tcAddImplicits things 
    438438       ; setGblEnv tcg_env thing_inside }