$ git clone -n https://src.fedoraproject.org/rpms/perl-CBOR-XS.git /var/lib/mock/f40-build-2243388-53669/root/chroot_tmpdir/scmroot/perl-CBOR-XS
Cloning into '/var/lib/mock/f40-build-2243388-53669/root/chroot_tmpdir/scmroot/perl-CBOR-XS'...
$ git fetch origin b8783f8762c0057fdc814267a1bf314ad092d5c3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-CBOR-XS
 * [new ref]         b8783f8762c0057fdc814267a1bf314ad092d5c3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b8783f8 1.87 bump