$ git clone -n https://src.fedoraproject.org/rpms/tigervnc.git /var/lib/mock/f41-build-side-1-2771434-32231/root/chroot_tmpdir/scmroot/tigervnc
Cloning into '/var/lib/mock/f41-build-side-1-2771434-32231/root/chroot_tmpdir/scmroot/tigervnc'...
$ git fetch origin 106aed8c140a74db8e77624f2d1c91b3a7be7cc0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/tigervnc
 * [new ref]         106aed8c140a74db8e77624f2d1c91b3a7be7cc0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 106aed8 Add BR: libxcvt