$ git clone -n https://src.fedoraproject.org/rpms/rubygem-useragent.git /var/lib/mock/f45-build-35412-695/root/chroot_tmpdir/scmroot/rubygem-useragent
Cloning into '/var/lib/mock/f45-build-35412-695/root/chroot_tmpdir/scmroot/rubygem-useragent'...
$ git fetch origin b84280785185cdbcf0dd733062537f777e05d929:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-useragent
 * [new ref]         b84280785185cdbcf0dd733062537f777e05d929 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b842807 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild