$ git clone -n https://src.fedoraproject.org/rpms/rubygem-fog-json.git /var/lib/mock/f42-build-3458053-45512/root/chroot_tmpdir/scmroot/rubygem-fog-json
Cloning into '/var/lib/mock/f42-build-3458053-45512/root/chroot_tmpdir/scmroot/rubygem-fog-json'...
$ git fetch origin ea918a7ddcc44953d5da1cb7a84bde6e1585c064:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-fog-json
 * [new ref]         ea918a7ddcc44953d5da1cb7a84bde6e1585c064 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ea918a7 Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild