$ git clone -n https://github.com/xcp-ng-rpms/swtpm.git /var/lib/mock/v8.3-u-pcoval2-10158-28749/root/chroot_tmpdir/scmroot/swtpm
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10158-28749/root/chroot_tmpdir/scmroot/swtpm'...
$ git fetch origin 39be3991d53dda9ece7c1836f4df50407ba40b8e:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/swtpm
 * [new ref]         39be3991d53dda9ece7c1836f4df50407ba40b8e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 39be399 bump release for test build