$ git clone -n https://github.com/xcp-ng-rpms/coreutils /var/lib/mock/v8.3-incoming-10637-29191/root/chroot_tmpdir/scmroot/coreutils
Cloning into '/var/lib/mock/v8.3-incoming-10637-29191/root/chroot_tmpdir/scmroot/coreutils'...
$ git fetch origin ec1fd600746d31b6e6b5ad5296fa3397dea9f0f6:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/coreutils
 * [new ref]         ec1fd600746d31b6e6b5ad5296fa3397dea9f0f6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ec1fd60 Merge pull request #1 from xcp-ng-rpms/8.3-XS-1557