$ git clone -n https://src.fedoraproject.org/rpms/rubygem-net-irc.git /var/lib/mock/f45-build-35080-693/root/chroot_tmpdir/scmroot/rubygem-net-irc
Cloning into '/var/lib/mock/f45-build-35080-693/root/chroot_tmpdir/scmroot/rubygem-net-irc'...
$ git fetch origin 08a3b7569fae74579776317eb7a6b85959be8948:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-net-irc
 * [new ref]         08a3b7569fae74579776317eb7a6b85959be8948 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 08a3b75 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild