#15002: Panic: collectNBinders -------------------------------------+------------------------------------- Reporter: crockeea | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.4.2 Component: Profiling | Version: 8.4.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nomeata): Thanks for the bisecting and minimization! Exemplary bug reporting! Judging from the report and the fact that profiling is necessary, it looks like profiling breaks the invariant that a joint point has `Lam`s as their right-hand-side. This can be confirmed by extending the `pprPanic` in `collectNBinders` to also show `orig_expr`. It might just be a case of looking through `Tick`s … but I am no expert on how profiled GHC is supposed to be handled. I am building the current `master` to look into it, but I don’t expect the build to finish in time to actually do that today. Unless someone beats me to it, I’ll have a lock tomorrow. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15002#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler