[fedora-virt] libguestfs vs parallel make

[Jim Meyering <jim meyering net>]

Hi Rich,

I noticed that the recommended idiom

    make %{?_smp_mflags}

is not used in libguestfs.spec.
This comment:

    # Uses javac which is incompatible with parallel make.
    make INSTALLDIRS=vendor

makes me think you can enable parallel builds overall,
and turn off parallelism only in the java/ sub-directory.
To do that, simply add these lines to java/Makefile.am:

    # Tell version 3.79 and up of GNU make to not build goals in this
    # directory in parallel.
    .NOTPARALLEL: