$ git clone -n https://src.fedoraproject.org/rpms/rubygem-rack-accept.git /var/lib/mock/f45-build-35267-694/root/chroot_tmpdir/scmroot/rubygem-rack-accept
Cloning into '/var/lib/mock/f45-build-35267-694/root/chroot_tmpdir/scmroot/rubygem-rack-accept'...
$ git fetch origin fe9740b498389e40b3516b9828960b121dca2fb1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-rack-accept
 * [new ref]         fe9740b498389e40b3516b9828960b121dca2fb1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fe9740b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild