$ git clone -n https://github.com/xcp-ng-rpms/swtpm /var/lib/mock/v8.3-incoming-8945-27879/root/chroot_tmpdir/scmroot/swtpm
Cloning into '/var/lib/mock/v8.3-incoming-8945-27879/root/chroot_tmpdir/scmroot/swtpm'...
$ git fetch origin a2b894c6b87ce084050d0c45bc63f83bd4049b4c:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/swtpm
 * [new ref]         a2b894c6b87ce084050d0c45bc63f83bd4049b4c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a2b894c Merge branch 'XS-8.3' into 8.3-import_swtpm-0.7.3-9.xs8.src.rpm