$ git clone -n https://src.fedoraproject.org/rpms/libtdb.git /var/lib/mock/f45-build-17074-495/root/chroot_tmpdir/scmroot/libtdb
Cloning into '/var/lib/mock/f45-build-17074-495/root/chroot_tmpdir/scmroot/libtdb'...
$ git fetch origin 18be114f0f203d68dab89ffae6f2d236771c8a37:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libtdb
 * [new ref]         18be114f0f203d68dab89ffae6f2d236771c8a37 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 18be114 rhbz#2431270 - libtdb-1.4.15 is available