$ git clone -n https://src.fedoraproject.org/rpms/vnstat.git /var/lib/mock/f45-build-38167-722/root/chroot_tmpdir/scmroot/vnstat
Cloning into '/var/lib/mock/f45-build-38167-722/root/chroot_tmpdir/scmroot/vnstat'...
$ git fetch origin f5762f5bccfa9ceec9dc1ecb48673a9cbde91fc1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vnstat
 * [new ref]         f5762f5bccfa9ceec9dc1ecb48673a9cbde91fc1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f5762f5 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild