$ git clone -n https://src.fedoraproject.org/rpms/rubygem-htmlentities.git /var/lib/mock/f45-build-34982-692/root/chroot_tmpdir/scmroot/rubygem-htmlentities
Cloning into '/var/lib/mock/f45-build-34982-692/root/chroot_tmpdir/scmroot/rubygem-htmlentities'...
$ git fetch origin 917a5a7cb99ee2e69cf3d77977ed7e522a51928a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-htmlentities
 * [new ref]         917a5a7cb99ee2e69cf3d77977ed7e522a51928a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 917a5a7 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild