$ git clone -n https://github.com/xcp-ng-rpms/libarchive.git /var/lib/mock/v8.3-u-pcoval2-10559-29115/root/chroot_tmpdir/scmroot/libarchive
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10559-29115/root/chroot_tmpdir/scmroot/libarchive'...
$ git fetch origin e99970d7f9d376fab09c8f852c6df5586e154ac6:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libarchive
 * [new ref]         e99970d7f9d376fab09c8f852c6df5586e154ac6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e99970d bump release for test build