$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-repo.git /var/lib/mock/v8.3-u-asultanov2-11461-29765/root/chroot_tmpdir/scmroot/xs-opam-repo
Cloning into '/var/lib/mock/v8.3-u-asultanov2-11461-29765/root/chroot_tmpdir/scmroot/xs-opam-repo'...
$ git fetch origin dbd76fe3dfb0a5769bd8a54ad29f517cef02aa9e:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xs-opam-repo
 * [new ref]         dbd76fe3dfb0a5769bd8a54ad29f517cef02aa9e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dbd76fe bump release for test build