Re: [GHC] #14158: (Control.Category.id @(->) >>=) causes GHC panic

#14158: (Control.Category.id @(->) >>=) causes GHC panic -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: merge Priority: normal | Milestone: 8.2.2 Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones ): In [changeset:"2c133b67df374c73bc8069cefd7d57e1d2a14fc3/ghc" 2c133b67/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="2c133b67df374c73bc8069cefd7d57e1d2a14fc3" Really fix Trac #14158 I dug more into how #14158 started working. I temporarily reverted the patch that "fixed" it, namely commit a6c448b403dbe8720178ca82100f34baedb1f47e Author: Simon Peyton Jones Date: Mon Aug 28 17:33:59 2017 +0100 Small refactor of getRuntimeRep Sure enough, there was a real bug, described in the new TcExpr Note [Visible type application zonk] In general, syntactic substituion should be kind-preserving! Maybe we should check that invariant... }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14158#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler