#12785: GHC panic, `tcTyVarDetails` is missing a case -------------------------------------+------------------------------------- Reporter: heisenbug | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: yes Blocked By: | Blocking: Related Tickets: #12590 | Differential Rev(s): Phab:D2931 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ryan Scott <ryan.gl.scott@…>): In [changeset:"560bc289fc6a5b308f985d4c84e0cdf1f88c55fd/ghc" 560bc289/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="560bc289fc6a5b308f985d4c84e0cdf1f88c55fd" Revert "Remove unnecessary isTyVar tests in TcType" Summary: This reverts commit a0899b2f66a4102a7cf21569889381446ce63833. This is because removing these checks prompts panics in at least two different programs reported in #12785. Test Plan: ./validate Reviewers: simonpj, goldfire, bgamari, austin Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2931 GHC Trac Issues: #12785 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12785#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler