On Wed, Dec 14, 2016 at 12:48 PM, Nathan Zachary <nathanzach...@gentoo.org> wrote: > On 14/12/16 10:11, Doug Freed wrote: >> On Wed, Dec 14, 2016 at 11:04 AM, Michał Górny <mgo...@gentoo.org> wrote: >>> On Wed, 14 Dec 2016 15:27:25 +0300 >>> Andrew Savchenko <birc...@gentoo.org> wrote: >>> >>>> On Tue, 13 Dec 2016 10:36:15 +0100 Michał Górny wrote: >>>>> + nproc=$(python -c 'import multiprocessing; >>>>> print(multiprocessing.cpu_count());' 2>/dev/null) >>>> This is not portable. E.g. paludis users can have python-less >>>> system. Adding dev-lang/python to DEPEND will be also a bad idea, >>>> since this is quite heavy dependency. >>> You can bikeshed potential circumstances where it wouldn't work for >>> the next year. Which doesn't change that it would work quite reliably >>> for the most of Gentoo users. >>> >>>> Since on Linux boxes nproc is from coreutils, which is in @system, >>>> so looks like only *bsd setups are the problem. On FreeBSD >>> ...and all other operating systems (see: Prefix). >>> >>>> sysctl -a | egrep -i 'hw.ncpu' >>> I somehow doubt that would give me the expected number only, and I lack >>> a BSD install handy to test it. >> $(sysctl -n hw.ncpu) >> > I don't know that the sysctl command works universally: > > # sysctl -n hw.ncpu > sysctl: cannot stat /proc/sys/hw/ncpu: No such file or directory >
It's BSD-specific (Darwin may have it too, but I'm not in OS X at the moment, so I can't check), which pretty much describes this branch in the codepath as well. Linux users will have the nproc command from coreutils. -Doug
