#13772: Cannot put HasCallStack on instances -------------------------------------+------------------------------------- Reporter: augustss | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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 simonpj): You can put implicit-parameter constraints on the methods, but not on the instance. If the instance had implicit-parameter constraints it'd become voisible exactly where the constraint was solved. So currently it's by design. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13772#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler