$ git clone -n https://github.com/xcp-ng-rpms/libarchive.git /var/lib/mock/v8.3-u-pcoval2-10310-28879/root/chroot_tmpdir/scmroot/libarchive
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10310-28879/root/chroot_tmpdir/scmroot/libarchive'...
$ git fetch origin d74b1f07d9c5694e1bcc192636a980af3de91dda:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/libarchive
 * [new ref]         d74b1f07d9c5694e1bcc192636a980af3de91dda -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d74b1f0 bump release for test build