$ git clone -n https://src.fedoraproject.org/rpms/swtpm.git /var/lib/mock/f39-build-1540401-36472/root/chroot_tmpdir/scmroot/swtpm
Cloning into '/var/lib/mock/f39-build-1540401-36472/root/chroot_tmpdir/scmroot/swtpm'...
$ git fetch origin 5bb7a5e9462f338ed63b6867aa07961599942d22:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/swtpm
 * [new ref]         5bb7a5e9462f338ed63b6867aa07961599942d22 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5bb7a5e Build for i686 again since dependency issue resolved