$ git clone -n https://github.com/xcp-ng-rpms/samba.git /var/lib/mock/v8.3-u-pcoval1-11272-29617/root/chroot_tmpdir/scmroot/samba
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11272-29617/root/chroot_tmpdir/scmroot/samba'...
$ git fetch origin 38eaaecf8e1a9d2696434c1de266f64b85a7380c:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/samba
 * [new ref]         38eaaecf8e1a9d2696434c1de266f64b85a7380c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 38eaaec bump release for test build