#13916: Optimizations create run time seg faults -------------------------------------+------------------------------------- Reporter: newthin | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (CodeGen) | Resolution: | Keywords: optimization Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): So to recap, `takeMVar` is getting passed a pointer that does not appear to point to an `MVar` closure. There are two reasons for this, 1. the closure was once an `MVar` but overwritten by someone since it was allocated (implying that whatever code overwrote the closure is at fault) 2. the pointer is invalid (implying that some parent in the callgraph may be at fault, or they took the pointer from another closure which itself was trampled on by someone else). I believe I've ruled out (1): watching the closure's memory suggests that there never was an `MVar` closure at this address. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13916#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler