$ git clone -n https://src.fedoraproject.org/rpms/mirrormanager2.git /var/lib/mock/f40-build-2613327-64062/root/chroot_tmpdir/scmroot/mirrormanager2
Cloning into '/var/lib/mock/f40-build-2613327-64062/root/chroot_tmpdir/scmroot/mirrormanager2'...
$ git fetch origin e0a799233e76af2c77750326a2e4e8784e39495a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mirrormanager2
 * [new ref]         e0a799233e76af2c77750326a2e4e8784e39495a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e0a7992 Require SQLAlchemy < 2