$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-repo.git /var/lib/mock/v8.3-u-asultanov2-11359-29670/root/chroot_tmpdir/scmroot/xs-opam-repo
Cloning into '/var/lib/mock/v8.3-u-asultanov2-11359-29670/root/chroot_tmpdir/scmroot/xs-opam-repo'...
$ git fetch origin 4a5814bbb726bcb9ba800aa7f38d4fdd51e0315b:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xs-opam-repo
 * [new ref]         4a5814bbb726bcb9ba800aa7f38d4fdd51e0315b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4a5814b bump release for test build