$ git clone -n https://src.fedoraproject.org/rpms/perl-MIME-Base64.git /var/lib/mock/f40-build-779491-130344/root/chroot_tmpdir/scmroot/perl-MIME-Base64
Cloning into '/var/lib/mock/f40-build-779491-130344/root/chroot_tmpdir/scmroot/perl-MIME-Base64'...
$ git fetch origin 9e08c18ae15991b951bd31a05c2e815333b6f7c8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-MIME-Base64
 * [new ref]         9e08c18ae15991b951bd31a05c2e815333b6f7c8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9e08c18 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild