Function run_subprocess

numpy/testing/_private/utils.py:2873–2899

Run ``cmd`` in a subprocess, failing the test with its captured output if it exits with a nonzero status. Output that a subprocess merely inherits is lost in pytest-xdist workers when a test fails, making CI failures hard to debug. Routing a build/compile/run step through this help

(cmd, cwd=None, **kwargs)

def run_subprocess(cmd, cwd=None, **kwargs):
    """Run ``cmd`` in a subprocess, failing the test with its captured output
    if it exits with a nonzero status.

    Output that a subprocess merely inherits is lost in pytest-xdist workers
    when a test fails, making CI failures hard to debug.  Routing a
    build/compile/run step through this helper captures the child's stdout and
    stderr and folds them into the failure message so they reach the report.
    Returns the ``subprocess.CompletedProcess`` for callers that want to
    inspect the output.  Extra keyword arguments are passed to
    ``subprocess.run``.
    """
    import subprocess

    import pytest

    res = subprocess.run(cmd, cwd=cwd, capture_output=True, text=True,
                         errors="replace", **kwargs)
    if res.returncode != 0:
        cmd_str = cmd if isinstance(cmd, str) else " ".join(map(str, cmd))
        in_dir = f" in {cwd}" if cwd is not None else ""
        pytest.fail(
            f"`{cmd_str}` failed (exit {res.returncode}){in_dir}\n"
            f"----- stdout -----\n{res.stdout}\n"
            f"----- stderr -----\n{res.stderr}",
            pytrace=False)
    return res