#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): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"f4a14d6c535bdf52b19f441fe185ea13d62fdc24/ghc" f4a14d6c/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="f4a14d6c535bdf52b19f441fe185ea13d62fdc24" Use substTyUnchecked in TcMType.new_meta_tv_x Sadly, one of the indirect callers of this function doesn't yet enforce the in-scope set. It's in the TcHsType.tc_infer_args swamp, so I'm not going to wade in there today. The assertion tripped when investigating Trac #12785; but this patch does NOT fix the actual bug reported there. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12785#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler