$ git clone -n https://src.fedoraproject.org/rpms/plplot.git /var/lib/mock/f42-build-3465154-45737/root/chroot_tmpdir/scmroot/plplot
Cloning into '/var/lib/mock/f42-build-3465154-45737/root/chroot_tmpdir/scmroot/plplot'...
$ git fetch origin f5e61906a6db55ddc6039316eaf6d0763bd12844:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plplot
 * [new ref]         f5e61906a6db55ddc6039316eaf6d0763bd12844 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f5e6190 Explicitly require tcl/tk 8 (rhbz#2337726)