#12127: ghc-8.0.1: panic! (the 'impossible' happened) filterImports/combine (double import) -------------------------------------+------------------------------------- Reporter: slyfox | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"393928db9fc35ef8bdeb241c051224a6c4bdf749/ghc" 393928db/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="393928db9fc35ef8bdeb241c051224a6c4bdf749" Fix renamer panic This patch fixes Trac #12216 and #12127. The 'combine' function in 'imp_occ_env' in RnNames.filterImports checked for an empty field-selector list, which was (a) unnecessary and (b) wrong. I've elaborated the comments. This does NOT fix #11959 which is related but not the same (it concerns bundling of pattern synonyms). }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12127#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler