NuProcess - Possible race condition on linux with fast exiting processes

NuProcessProblem.java

package playground;

import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionStage;
import java.util.concurrent.ExecutionException;

import com.zaxxer.nuprocess.NuAbstractProcessHandler;
import com.zaxxer.nuprocess.NuProcess;
import com.zaxxer.nuprocess.NuProcessBuilder;

/**
 * Launching with: 
 * java -jar nuprocessproblem.jar 1000 echo test
 * or
 * java -jar nuprocessproblem.jar 1000 bash -c "echo test"
 * produces on linux about ~ 5% failures
 * 
 * java -jar nuprocessproblem.jar 1000 bash -c "sleep 0.01 ; echo test"
 * works 100%
 */
public class NuProcessProblem {
	public static void main(String[] args) {
		int count = 100;
		List<String> command = new ArrayList<>();
		if (args.length > 0) {
			count = Integer.parseInt(args[0]);
			for (int i = 1 ; i < args.length ; i++) {
				command.add(args[i]);
			}
		}
		int success = 0, fail = 0;
		List<String> errors = new ArrayList<>();
		for (int i = 0 ; i < count ; i++) {
			try {
				startEchoProcess(command).toCompletableFuture().get();
				success++;
			} catch (InterruptedException | ExecutionException e) {
				errors.add(e.getLocalizedMessage());
				e.printStackTrace();
				fail++;
			}
		}
		System.out.println("All Errors: " + errors);
		System.out.println("Result: success: " + success + " / fail: " + fail);
	}
	
	public static CompletionStage<Void> startEchoProcess(List<String> command) {
		if (command.isEmpty()) {
			command = Arrays.asList("echo", "-i", "blubb", "-acodec", "libmp3lame", "-y", "asdf");
		}
		CompletableFuture<Void> completableFuture = new CompletableFuture<>();
		
		NuProcessBuilder builder = new NuProcessBuilder(command);
		builder.setProcessListener(new NuAbstractProcessHandler() {
			
			@Override
			public void onStdout(ByteBuffer buffer) {
				logOutput("STDOUT: ", buffer);
			}
			
			@Override
			public boolean onStdinReady(ByteBuffer buffer) {
				return false;
			}
			
			@Override
			public void onStderr(ByteBuffer buffer) {
				logOutput("STDERR: ", buffer);
			}
			
			@Override
			public void onStart(NuProcess nuProcess) {
				System.out.println("onStart");
			}
			
			@Override
			public void onExit(int exitCode) {
				System.out.println("onExit: " + exitCode);
				if (exitCode == 0) {
					completableFuture.complete(null);
				} else {
					completableFuture.completeExceptionally(new RuntimeException("exited with code: " + exitCode));
				}
			}
			private void logOutput(String prefix, ByteBuffer buffer) {
				if (buffer == null) {
					return;
				}
				byte[] buf = new byte[buffer.remaining()];
				buffer.get(buf);
				System.out.println(prefix + " " + new String(buf).trim());
			}
		});
		NuProcess process = builder.start();
		return completableFuture;
	}
}