$ git clone -n https://github.com/xcp-ng-rpms/xen.git /var/lib/mock/v8.3-incoming-8839-27777/root/chroot_tmpdir/scmroot/xen
Cloning into '/var/lib/mock/v8.3-incoming-8839-27777/root/chroot_tmpdir/scmroot/xen'...
$ git fetch origin 540c442ca4309517a7d3067e80e1d8e4b2ad4bde:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xen
 * [new ref]         540c442ca4309517a7d3067e80e1d8e4b2ad4bde -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 540c442 Merge pull request #65 from xcp-ng-rpms/8.3-rebase-XS-20250709