severity 816980 normal retitle 816980 julia: Please do not use more CPUs than available. thanks
Sorry, I can't reproduce this consistently, but when the problem happens, I see a segfault like this in dmesg: [ 5377.752190] julia[21086]: segfault at 20000ffe2 ip 00007f033628b807 sp 00007ffc819cbdb0 error 4 in libjulia.so[7f03361ed000+eb000] which I think it is the result of bad memory handling. Version 0.3 for this program used to build ok. Now the build is not reliable, at least for me. I think part of the problem is that parallel builds are enabled no matter the number of CPUs I have. In the logs, I see this: env JULIA_CPU_CORES=2 [...] and in fact debian/rules has this: # Set number of parallel workers for tests ifneq (,$(filter parallel=%,$(DEB_BUILD_OPTIONS))) TESTS_ENV += JULIA_CPU_CORES=$(patsubst parallel=%,%,$(filter parallel=%,$(DEB_BUILD_OPTIONS))) else ifeq (,$(filter parallel,$(DEB_BUILD_OPTIONS))) TESTS_ENV += JULIA_CPU_CORES=2 endif I'm not sure if this is policy compliant or not, but I think the number of cores to be used should be limited in either case by the number of actual CPUs available, as there is little point in using parallel builds (or parallel workers for test suite) when you have only one CPU. That's also a waste of memory because the build will never be faster that way when using a single CPU. So, I'm going to consider this as a (normal) bug in the build system itself: Please limit the number of concurrent tasks to the number of available CPUs (or just assume a single CPU if there is no "parallel=" in DEB_BUILD_OPTIONS). We have Build-Depends. We don't have Memory-Depends (yet). Autobuilders probably have plenty of memory, maybe more than the most memory demanding source package, but that does not mean we should waste memory by having processes in parallel when it means no gain in build time. Thanks.