#13434: hs_try_putmvar003 is timing out / segfaulting -------------------------------------+------------------------------------- Reporter: ezyang | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 8.1 Resolution: | Keywords: 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 ezyang): I was able to reproduce on a 64-bit Ubuntu machine. Here were my steps: 1. Download ghc-head from hvr's PPA https://launchpad.net/~hvr/+archive/ubuntu/ghc 2. Build the test case: `ghc-head -c hs_try_putmvar003.hs` and then ` ghc- head hs_try_putmvar003_c.c hs_try_putmvar003.o -debug` 3. Repeatedly run `./a.out 1 1 1 1 +RTS -DS` until it hangs or segfaults. In 25 runs, 4 failed in various different ways (assert fail, segfault, or deadlock.) It's a bit annoying because the C stub uses pthreads whether or not the threaded runtime is linked, so I don't have something that's deterministic. Scanning over the code, I didn't see anything obviously wrong, so I'm going to do some bisecting and see if this always failed or if it's a regression introduced by an unrelated change (levity polymorphism causing the unsafeCoerce to be bad, maybe?) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13434#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler