$ git clone -n https://src.fedoraproject.org/rpms/rubygem-http-cookie.git /var/lib/mock/f45-build-34989-692/root/chroot_tmpdir/scmroot/rubygem-http-cookie
Cloning into '/var/lib/mock/f45-build-34989-692/root/chroot_tmpdir/scmroot/rubygem-http-cookie'...
$ git fetch origin 5e3755a625a3496bbcb5301248656e7d9ed8c577:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-http-cookie
 * [new ref]         5e3755a625a3496bbcb5301248656e7d9ed8c577 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5e3755a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild