$ git clone -n https://src.fedoraproject.org/rpms/GraphicsMagick.git /var/lib/mock/f40-build-2236701-53519/root/chroot_tmpdir/scmroot/GraphicsMagick
Cloning into '/var/lib/mock/f40-build-2236701-53519/root/chroot_tmpdir/scmroot/GraphicsMagick'...
$ git fetch origin 52c2af1935a7c3058acce74b8876ba35bd3e9738:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/GraphicsMagick
 * [new ref]         52c2af1935a7c3058acce74b8876ba35bd3e9738 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 52c2af1 Rebuild for jasper 4.1