the current process, and running one benchmark file in a fresh child process.

To access it:

* `path` {string} The absolute path of one benchmark module.

* `options` {Object}

* `env` {Object} The child process environment. Property values must be

strings or `undefined`. This replaces, rather than extends, the parent

environment. **Default:** A snapshot of `process.env`.

* `execArgv` {string\[]} Node.js command-line options for the child process.

This replaces, rather than extends, inherited options. Benchmark runner

options, positional arguments, and options that select another execution

mode are not allowed. **Default:** Compatible options inherited from the

current process.

* `signal` {AbortSignal} Terminates the child process when aborted.

* Returns: {BenchmarksStream}

Runs exactly one benchmark module in a fresh child process and returns its

object-mode event stream. `path` is not interpreted as a glob. Unless the signal

is aborted or the stream is destroyed before startup, every call uses a new

child. Input discovery, ordering, concurrency, retries, and multi-file

scheduling remain the caller's responsibility.

Records use advanced child process serialization, preserving supported

structured values such as `bigint` and errors. Child writes to stdout and stderr

become `'bench:diagnostic'` records. A module loading error, abnormal child exit,

or cancellation also emits an error diagnostic and produces a terminal

`'bench:summary'` whose `success` property is `false`; these execution failures

do not error the stream. If module evaluation fails after declaring benchmarks,

those declarations still run before the unsuccessful summary.

`env`, effective inherited options, and an explicitly provided `execArgv` are

copied when `runFile()` is called. The runner removes `NODE_OPTIONS`, replaces

IPC-related environment variables, and sets its private child-context, run

identity, and file identity variables, overriding properties with those names

in `env`. Pass child Node.js options through `execArgv`, not `NODE_OPTIONS`.

Standard `child_process` environment propagation still applies, including

`NODE_V8_COVERAGE`, permission-model options, and required z/OS variables.

Aborting `signal` before the child starts produces an `AbortError` diagnostic

without spawning it. Aborting during execution sends `SIGTERM` to the child and

escalates to `SIGKILL` if it does not exit. Destroying the returned stream

follows the same termination procedure.