$ git clone -n https://src.fedoraproject.org/rpms/rubygem-guard.git /var/lib/mock/f39-build-1541076-36480/root/chroot_tmpdir/scmroot/rubygem-guard
Cloning into '/var/lib/mock/f39-build-1541076-36480/root/chroot_tmpdir/scmroot/rubygem-guard'...
$ git fetch origin f9da8c33b47aa7905c6d5eb2cd2c3f16ffbd79b5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-guard
 * [new ref]         f9da8c33b47aa7905c6d5eb2cd2c3f16ffbd79b5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f9da8c3 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild