$ git clone -n https://src.fedoraproject.org/rpms/libwnck.git /var/lib/mock/f45-build-17260-497/root/chroot_tmpdir/scmroot/libwnck
Cloning into '/var/lib/mock/f45-build-17260-497/root/chroot_tmpdir/scmroot/libwnck'...
$ git fetch origin b5828544c1188e4e6312a0b4462dda6e9ae3fe44:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libwnck
 * [new ref]         b5828544c1188e4e6312a0b4462dda6e9ae3fe44 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b582854 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild