$ git clone -n https://src.fedoraproject.org/rpms/rubygem-webmock.git /var/lib/mock/f45-build-35392-695/root/chroot_tmpdir/scmroot/rubygem-webmock
Cloning into '/var/lib/mock/f45-build-35392-695/root/chroot_tmpdir/scmroot/rubygem-webmock'...
$ git fetch origin b675a0673de47f4629cdb6fd464d68f18725e1fa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-webmock
 * [new ref]         b675a0673de47f4629cdb6fd464d68f18725e1fa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b675a06 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild