$ git clone -n https://src.fedoraproject.org/rpms/dtk6widget.git /var/lib/mock/f42-build-side-1-3568059-46743/root/chroot_tmpdir/scmroot/dtk6widget
Cloning into '/var/lib/mock/f42-build-side-1-3568059-46743/root/chroot_tmpdir/scmroot/dtk6widget'...
$ git fetch origin ca88c7bc7eaa381d34ed267dab1f337313aa0960:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dtk6widget
 * [new ref]         ca88c7bc7eaa381d34ed267dab1f337313aa0960 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ca88c7b Rebuild (qt6)