$ git clone -n https://github.com/xcp-ng-rpms/wget.git /var/lib/mock/v8.3-u-pcoval2-10031-28678/root/chroot_tmpdir/scmroot/wget
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10031-28678/root/chroot_tmpdir/scmroot/wget'...
$ git fetch origin b4919574e4be1385e70f4cb14997c449e4fd41a4:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/wget
 * [new ref]         b4919574e4be1385e70f4cb14997c449e4fd41a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b491957 bump release for test build