#14111: strange error when using data families with levity polymorphism and unboxed sums and data families -------------------------------------+------------------------------------- Reporter: carter | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: 13737 | Blocking: Related Tickets: #14457 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Phab:D4974 purports to "get rid of the whole knot-tying business"... or so I thought. Actually, I don't think even Phab:D4974 would be sufficient to unblock this. The problem is that even with that patch, `res_tmpl` in comment:14 is //still// knot-tied (since it mentions the knot-tied `rep_tycon`). This means calling `unifyType` on it is doomed to loop infinitely. Alas, https://phabricator.haskell.org/D4974#137148 suggests that `rep_tycon` is destined to be knot-tied, so I'm not sure how this bug could ever be fixed. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14111#comment:19 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler