Function run

nix/build-all.py:475–518

Wraps `subprocess.Popen.communicate()` and logs the command being executed, sets up logging `stderr` to `LOG_FILE` (in append mode) and returns stdout with leading and trailing whitespace removed.

(cmds: "Sequence[str]", cwd: "Union[str, None]" = None, can_fail: bool = False)

def run(cmds: "Sequence[str]", cwd: "Union[str, None]" = None, can_fail: bool = False) -> str:
    """
    Wraps `subprocess.Popen.communicate()` and logs the command being executed,
    sets up logging `stderr` to `LOG_FILE` (in append mode) and returns stdout
    with leading and trailing whitespace removed.
    """

    def timestamp() -> str:
        return datetime.now().strftime("%Y-%m-%d %H:%M:%S,%f")[:-3]  # same format as logging

    def stream_reader(pipe, collector: "list[str]", log_file) -> None:
        for line in iter(pipe.readline, ""):
            log_file.write(f"{timestamp()} {line}")
            log_file.flush()
            collector.append(line)
        pipe.close()

    logger.debug(f"running command `{' '.join(cmds)}` in directory '{cwd}'")
    stdout: list[str] = []
    stderr: list[str] = []

    # Ensure both live logs available in the log file
    # and the putput.
    with open(LOG_FILE, "a", encoding="utf-8") as log_file_handle:
        proc = sp.Popen(cmds, cwd=cwd, stdout=sp.PIPE, stderr=sp.PIPE, encoding="utf-8")
        assert proc.stdout and proc.stderr

        t_out = threading.Thread(target=stream_reader, args=(proc.stdout, stdout, log_file_handle))
        t_err = threading.Thread(target=stream_reader, args=(proc.stderr, stderr, log_file_handle))
        t_out.start()
        t_err.start()
        t_out.join()
        t_err.join()
        proc.wait()

    logger.debug(f"command returned {proc.returncode}")

    if proc.returncode != 0 and not can_fail:
        print("-" * 70)
        print("".join(stderr))
        print("-" * 70)
        raise RuntimeError(f"Command `{' '.join(cmds)}` returned exit code {proc.returncode}")

    return "".join(stdout).strip()


if platform.system() == "Darwin":