[Bug]: SubProcess Kernel not able to find return file

[svetakvsundhar]

What happened?

In attempting to run the ExampleEchoPipeline, I am facing a stacktrace like the following:

[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.6.0:java (default-cli) on project word-count-beam: An exception occured while executing the Java class. java.lang.Exception: Unexpected error runnng process. /home/svetaksundhar/Echo,/home/svetaksundhar/0344a6ae-b37a-4495-8370-c9a1ce97c186.res,2743 error message was 
[ERROR] Process succeded but no result file was found 
[ERROR] Command info was /home/myusername/Echo,/home/myusername0344a6ae-b37a-4495-8370-c9a1ce97c186.res,2743 
[ERROR] First line of error file is  null 
[ERROR] First line of out file is null 
[ERROR] First line of ret file is  

but, when I run a simple "Hello, World" statement through the Echo.cc C++ file, it writes to results.txt as intended.

./Echo /home/myusername/result.txt "Hello, world!"

The ExampleEchoPipelineTest fails locally with the same error as well.

I'm running with the following mvn command on the word-count-beam project

mvn compile exec:java -Dexec.mainClass=org.apache.beam.examples.subprocess.ExampleEchoPipeline                       -Dexec.args="--sourcePath=/home/myusername\
                                   --workerPath=/home/myusername \
                                   --concurrency=5 \
                                   --filesToStage=/home/myusername/Echo,/home/myusername/EchoAgain 

Issue Priority

Priority: 1 (data loss / total loss of function)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam YAML
• Component: Beam examples
• Component: Beam playground
• Component: Beam katas
• Component: Website
• Component: Infrastructure
• Component: Spark Runner
• Component: Flink Runner
• Component: Samza Runner
• Component: Twister2 Runner
• Component: Hazelcast Jet Runner
• Component: Google Cloud Dataflow Runner