$ git clone -n https://src.fedoraproject.org/rpms/magic.git /var/lib/mock/f40-build-2009927-45537/root/chroot_tmpdir/scmroot/magic
Cloning into '/var/lib/mock/f40-build-2009927-45537/root/chroot_tmpdir/scmroot/magic'...
$ git fetch origin 92bedb41baf28297b9b6d6f04edeb1102fb54fff:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/magic
 * [new ref]         92bedb41baf28297b9b6d6f04edeb1102fb54fff -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 92bedb4 8.3.453