Re: [GHC] #8155: Defaulting bug or unfortunate error message with closed type families

#8155: Defaulting bug or unfortunate error message with closed type families --------------------------+------------------------------------------------ Reporter: nh2 | Owner: Type: bug | Status: closed Priority: | Milestone: normal | Component: | Version: 7.6.3 Compiler | Resolution: fixed | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Type of failure: | Test Case: indexed_types/should_fail/T8155 None/Unknown | Blocked By: | Blocking: Related Tickets: | --------------------------+------------------------------------------------ Comment (by Simon Peyton Jones ): In [changeset:"a94b484715d3caf445a7069377d5311e0e50f66e/ghc" a94b4847/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="a94b484715d3caf445a7069377d5311e0e50f66e" Back-pedal the fix for Trac #8155 I implemented a rather elaborate fix for #8155 ages ago, which which turns out to be a) unnecesssary in this particular case b) harmful to the defaulting story; see comment:15 of #12923. So this patch reverts the elaborate bit. The bit I removed is described in "Historical note" under Note [approximateWC]. }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8155#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler