how can i tell rpmbuild to *not* parallelize make during the build?

[Robert P. J. Day]

On Mon, 10 Feb 2014, Rick Stevens wrote:

> On 02/10/2014 12:09 PM, Robert P. J. Day issued this missive:
> >
> >    grrrrrr ... following the instructions here:
> >
> > https://fedoraproject.org/wiki/Building_a_custom_kernel
> >
> > on how to build a custom kernel (some of which is incorrect, more on
> > that later), and builds keep failing at random places, i'm guessing
> > because i have a hyperthreaded quad-core laptop, and the "make -j8" is
> > simply tripping over itself in arbitrary places.
> >
> >    what's the easiest way to specify a single-threaded build? yes, it
> > will take forever, but it will be nice to verify that that's the
> > problem.
> >
> >    thanks.
> >
> > rday
>
> Theoretically you could do
>
> 	MAKEFLAGS="-j 1" rpmbuild blah-blah
>
> gmake looks for the environment variable "MAKEFLAGS". Most reasonable
> makefiles do "MAKEFLAGS+=other-specific-flags", so it should honor it.
> Keep in mind that if there are multiple "-j" variables to gmake, it will
> only honor the LAST one specified. YMMV.

  well, this is interesting ... i found the variable "smp_mflags" in
kernel.spec, so i ran:

  $ rpmbuild --showrc

to see how it was being set, and found the following:

-14: _smp_mflags        %(
    [ -z "$RPM_BUILD_NCPUS" ] \
        && RPM_BUILD_NCPUS="`/usr/bin/nproc 2>/dev/null || \
                             /usr/bin/getconf _NPROCESSORS_ONLN`"; \
    if [ "$RPM_BUILD_NCPUS" -gt 16 ]; then \
        echo "-j16"; \
    elif [ "$RPM_BUILD_NCPUS" -gt 3 ]; then \
        echo "-j$RPM_BUILD_NCPUS"; \
    else \
        echo "-j3"; \
    fi )

which i find fascinating since, if you follow the logic, even if you
use "RPM_BUILD_NCPUS=1", that code above will still set it to 3. :-)

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

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