$ git clone -n https://src.fedoraproject.org/rpms/kcalc.git /var/lib/mock/f42-build-3279362-41337/root/chroot_tmpdir/scmroot/kcalc
Cloning into '/var/lib/mock/f42-build-3279362-41337/root/chroot_tmpdir/scmroot/kcalc'...
$ git fetch origin 91c1b77bdb5e60f152e8753ce7053f180796c9a7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kcalc
 * [new ref]         91c1b77bdb5e60f152e8753ce7053f180796c9a7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 91c1b77 Rebuild for ppc64le enablement