$ git clone -n https://src.fedoraproject.org/rpms/magic.git /var/lib/mock/f41-build-843193-161914/root/chroot_tmpdir/scmroot/magic
Cloning into '/var/lib/mock/f41-build-843193-161914/root/chroot_tmpdir/scmroot/magic'...
$ git fetch origin 949097dcee030b6f229b6815b42a2d3b64f9c001:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/magic
 * [new ref]         949097dcee030b6f229b6815b42a2d3b64f9c001 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 949097d 8.3.488