$ git clone -n https://src.fedoraproject.org/rpms/php-mongodb.git /var/lib/mock/f42-build-side-1-3499876-45966/root/chroot_tmpdir/scmroot/php-mongodb
Cloning into '/var/lib/mock/f42-build-side-1-3499876-45966/root/chroot_tmpdir/scmroot/php-mongodb'...
$ git fetch origin 5184f5bd13da61084025d41460ba9c63a120947f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/php-mongodb
 * [new ref]         5184f5bd13da61084025d41460ba9c63a120947f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5184f5b update to 1.21.1 (no change)