$ git clone -n https://src.fedoraproject.org/rpms/yash.git /var/lib/mock/f45-build-39299-733/root/chroot_tmpdir/scmroot/yash
Cloning into '/var/lib/mock/f45-build-39299-733/root/chroot_tmpdir/scmroot/yash'...
$ git fetch origin 18b375741533dc010e150afe81e3e8b12e1c6a91:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/yash
 * [new ref]         18b375741533dc010e150afe81e3e8b12e1c6a91 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 18b3757 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild