Log (undef, "docker image hash is $docker_hash");
$docker_stream =~ s/^\.//;
my $docker_install_script = qq{
-if $docker_bin images -q --no-trunc --all | grep -qxF \Q$docker_hash\E; then
+if $docker_bin images -q --no-trunc --all | grep -xF \Q$docker_hash\E >/dev/null; then
exit 0
fi
declare -a exit_codes=("\${PIPESTATUS[@]}")