﻿id summary reporter owner description type status priority milestone component version resolution keywords cc os architecture failure testcase blockedby blocking related differential 7185 Compiled program crashes waldheinz simonmar "I have a program which compiles fine, but the resulting executable crashes. First the steps to reproduce: {{{ git clone git@github.com:waldheinz/bling.git git checkout e2bad3ca6be2409386d28796997709318cf6ff64 cabal configure cabal build ./dist/build/bling/bling examples/cornell-box-underwater.bling }}} This will result in either a segfault or produce an ""internal error"" message, at least for me and two other who tried it as well. The error message is {{{ bling: internal error: scavenge_one: strange object -1083673327 (GHC version 7.7.20120823 for x86_64_unknown_linux) }}} The ""strange object"" varies. Some random observations which might be useful: * this happens with GHC 7.4.1 and a fresh compile of HEAD (GHC version 7.7.20120823) * I sanitized the code to be completely free of unsafe* function calls. Before, there was quite some unsafe array reading/writing using the vector package. This did not change anything, but the revision above reflects this ""safe"" state, just in case... * the problem first occured when I change the SPPM.mkHash function to use the Utils.GrowVec type instead of lists for it's intermediate results. [1] GrowVec is basically a wrapper around a vector which doubles the size when space is exhausted. * the optimization level does not seem to affect the problem (it occurs even with -O0 and everything else removed) Running under GDB gives this stack trace: {{{ #1 0x00000031d12370d8 in abort () from /lib64/libc.so.6 #2 0x0000000000cb4765 in rtsFatalInternalErrorFn () #3 0x0000000000cb48dd in barf () #4 0x0000000000cd30e9 in scavenge_one () #5 0x0000000000cd3645 in scavenge_mutable_list () #6 0x0000000000cd3835 in scavenge_capability_mut_lists () #7 0x0000000000cb98bc in GarbageCollect () #8 0x0000000000cac043 in scheduleDoGC.isra.20 () #9 0x0000000000cacabf in scheduleWaitThread () #10 0x0000000000cb683e in real_main () #11 0x0000000000cb693a in hs_main () #12 0x0000000000407003 in main () }}} I'm currently trying to debug this further, but my abilities on this front are limited... [1] https://github.com/waldheinz/bling/commit/e1dc7b3c7e66cdd21a5aa46f9f96ca9448c52407#commitcomment-1761893" bug closed high 7.6.1 Compiler 7.4.1 fixed Linux x86_64 (amd64) Runtime crash