Hi John -- Since everyone here is sprinting toward the code freeze for 1.11, I'll send out a pointer rather than diving into an analysis at present:
Have you discovered the CHPL_COMM_USE_GDB environment variable described in doc/[release/]README.executing? With it and GASNet, you can run your program, popping up an xterm per locale which tends to work for failures that fail on a small number of nodes (< 4 or so). Compiling with -g and --cpp-lines and running with the --gdb flag should cause the program to break when this error is printed out, permitting you to get the stack trace that led to the error, which may help. If you get a stack trace but still can't determine why the error is occurring, feel free to send it along. -Brad On Mon, 16 Mar 2015, John MacFrenz wrote: > Hi, > > I'm having a problem where my program fails with error: > /home/john/projects/chapel/chapel/modules/internal/ChapelArray.chpl:165: > error: attempt to dereference nil > > I haven't had success in trying to isolate the problem so unfortunately I > don't have a simple example file which would reproduce the problem. However I > have a test in my git branch of chapel which causes the problem. The branch > in question is here > https://github.com/jfrenz/chapel/tree/VariBlockDist > The failing test is located at > test/distributions/jfrenz/block-variblock/simple-coexist.chpl . If you > comment out either of the forall loops in that file it runs fine. I have had > it fail at least with GASNET_SPAWNFN=L and two or four locales. > > In that git branch I have modified only files in modules/dists , > modules/standard and in test . > > Chpl info: > > CHPL_HOST_PLATFORM: linux64 > CHPL_HOST_COMPILER: gnu > CHPL_TARGET_PLATFORM: linux64 > CHPL_TARGET_COMPILER: gnu > CHPL_TARGET_ARCH: unknown > CHPL_LOCALE_MODEL: flat > CHPL_COMM: gasnet > CHPL_COMM_SUBSTRATE: udp > CHPL_GASNET_SEGMENT: everything > CHPL_TASKS: fifo > CHPL_LAUNCHER: amudprun > CHPL_TIMERS: generic > CHPL_MEM: cstdlib > CHPL_MAKE: make > CHPL_ATOMICS: intrinsics > CHPL_NETWORK_ATOMICS: none > CHPL_GMP: gmp > CHPL_HWLOC: none > CHPL_REGEXP: re2 > CHPL_WIDE_POINTERS: struct > CHPL_LLVM: none > CHPL_AUX_FILESYS: none > > ------------------------------------------------------------------------------ > Dive into the World of Parallel Programming The Go Parallel Website, sponsored > by Intel and developed in partnership with Slashdot Media, is your hub for all > things parallel software development, from weekly thought leadership blogs to > news, videos, case studies, tutorials and more. Take a look and join the > conversation now. http://goparallel.sourceforge.net/ > _______________________________________________ > Chapel-bugs mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/chapel-bugs > ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Chapel-bugs mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/chapel-bugs
