shell.exec() has odd issues with line breaks in the returned output

[davidm-ro]

macOS 15.5.

Using this Python script:

test.py:

#!/usr/bin/env python3

def main():
    print("Hello, World!")

if __name__ == "__main__":
    main()

If I execute a train script:

log("Testing Python script with single argument...");
try {
    var result = shell.exec("/usr/bin/python3", "test.py", {
        timeout: 60,
        capture: true,
        workdir: "."
    });
    log("Result: '" + result + "'");
    log("Expected: Hello World and line break");
} catch (e) {
    log("Error: " + e);
}

log("Testing Python script with multiple arguments...");
try {
    var result = shell.exec("/usr/bin/python3", "test.py --validate-only", {
        timeout: 60,
        capture: true,
        workdir: "."
    });
    log("Result: '" + result + "'");
    og("Expected: Hello World and one line break");
} catch (e) {
    log("Error: " + e);
}

Expected vs Observed

For both, to see simple 'Hello world'. For the first, I get nothing: result is ''. That may be the same as #54 .

For the second, I do get the captured output! But I get two line breaks:

  shell.exec(/usr/bin/python3 test.py --validate-only) { }   
  Result: 'Hello, World!

'