Re: [Libguestfs] Ocaml and pthread_atfork()

On Thu, May 03, 2012 at 02:00:27PM +1000, Tony Breeds wrote: > Hi All, > Firstly I apologize if this is noise. I elected to not file a > bugzilla as the problem seems to be powerpc specific and with the limited > resources for Fedora developers it would seem unfair. > > I was recently trying to build a "current" libguestfs from the f16 > branch[1]. During the build I hit: > > (extracted from rpmbuild) > > [tony@sneetch ~]$ bash -x tmp/ocaml-test.sh > + cd rpmbuild/BUILD/libguestfs-1.16.9/ocaml/ > + LD_LIBRARY_PATH=../src/.libs > + ocamlfind ocamlc -g -warn-error CDEFLMPSUVYZX -I . -package unix,threads -thread -linkpkg mlguestfs.cma t/guestfs_070_threads.cmo -o t/guestfs_070_threads.bc > File "_none_", line 1, characters 0-1: > Error: Error on dynamically loaded library: /usr/lib64/ocaml/stublibs/dllthreads.so: /usr/lib64/ocaml/stublibs/dllthreads.so: undefined symbol: pthread_atfork > > I did a quick bit of googling and found: > http://ryanarn.blogspot.com.au/2011/07/curious-case-of-pthreadatfork-on.html > > which seems to explain what's going on to my naive eye anyway. > > I've tried a few different CFLAGS/patches to > otherlibs/systhreads/Makefile to try and induce pthreads_atfork() to be > resolved and linked during the ocaml build. Nothing I try works. > > Does anyone have any ideas on how to solve this? > > I'm happy to do the heavy lifting I just don't have the background in > ocaml to solve this by myself. > > Yours Tony > > [1] I suspects that as a result of the demotion to secondary and things > languishing there we skipped a few builds. It looks like the PPC64 OCaml package is buggy. Can you compile any threaded program at all, eg: echo 'print_endline "hello"' > test.ml ocamlfind c -package threads -thread test.ml -linkpkg -o test ./test

Unfortunately I don't have access to ppc64, so there's no way I can even look at bugs in this area, let alone fix them.