#12100: GHC 8.0.1 build segmentation fault in haddock -------------------------------------+------------------------------------- Reporter: ilovezfs | Owner: Type: bug | Status: infoneeded Priority: highest | Milestone: 8.0.3 Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: MacOS X | Architecture: Type of failure: Building GHC | Unknown/Multiple failed | Test Case: Blocked By: | Blocking: Related Tickets: #11744, #11951 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by pggiarrusso): It's a start, since it gives the crashing position (`initGcThreads + 674 (GC.c:818)`) and suggests the runtime system is possibly (though not necessarily) involved. However, it seems the failing binary is not literally 8.0.1, so the line number might be out of sync. What's the source of the `ghc8.0.1.20161117` you're using? A stacktrace could be a bit better. Below, what I can analyze out of this dump, which isn't that much really. I suspect we'd need an actual coredump. https://github.com/ghc/ghc/blob/ghc-8.0.1-release/rts/sm/GC.c#L818 is an unlikely source of a crash. (But my best guess, based on a snapshot of ghc-8.0 with that date, suggests the affected code is https://github.com/ghc/ghc/blob/58d9f9b7a7f1b4d2c94183b9b9428983e7c83fe9/rts..., which is similarly surprising). If either is accurate, we have a segfault when writing *in the middle* of `gen_workspace *ws`. If the source tree matches commit commit 58d9f9b7a7f1b4d2c94183b9b9428983e7c83fe9, given the type definition in https://github.com/ghc/ghc/blob/58d9f9b7a7f1b4d2c94183b9b9428983e7c83fe9/rts..., the crash is when writing to field `ws->todo_large_objects`, which starts 64 bytes after the start of `ws`. `ws` is 64-bytes aligned, so this is plausible (if `ws->todo_large_objects` points to the beginning of a page). Strangely, no register in the dump has the right alignment to be such a `ws`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12100#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler