google/zx · error · Fail

Trying to abort a process without creating one.

Error message

Trying to abort a process without creating one.

What it means

Thrown by ProcessPromise.abort() when this.child is null — i.e. the underlying child process has not been spawned yet. The AbortController has nothing to signal before the process starts running.

Source

Thrown at src/core.ts:441

      this._stage = 'fulfilled'
      this._resolve(output)
    } else {
      this._stage = 'rejected'
      if (legacy) {
        this._resolve(output) // to avoid unhandledRejection alerts
        throw output.cause || output
      }
      this._reject(output)
      if (this.sync) throw output
    }
  }

  abort(reason?: string) {
    if (this.isSettled()) throw new Fail('Too late to abort the process.')
    if (this.signal !== this.ac.signal)
      throw new Fail('The signal is controlled by another process.')
    if (!this.child)
      throw new Fail('Trying to abort a process without creating one.')

    this.ac.abort(reason)
  }

  kill(signal?: NodeJS.Signals | null): Promise<void> {
    if (this.isSettled()) throw new Fail('Too late to kill the process.')
    if (!this.child)
      throw new Fail('Trying to kill a process without creating one.')
    if (!this.pid) throw new Fail('The process pid is undefined.')

    return $.kill(this.pid, signal || this._snapshot.killSignal || $.killSignal)
  }

  // Configurators
  stdio(
    stdin: IOType | StdioOptions,
    stdout: IOType = 'pipe',
    stderr: IOType = 'pipe'

View on GitHub (pinned to 00a2c484e2)

Solutions

1. Ensure the process has started: for halted promises call `pp.run()` first.
2. Defer the abort a tick: `setImmediate(() => pp.abort())`.
3. Abort from the 'start' event or use $.timeout for bounded behavior.

Example fix

// before
const pp = $({ halt: true })`sleep 10`
pp.abort()
// after
const pp = $({ halt: true })`sleep 10`
pp.run()
pp.abort()

// child is private; ensure the process is running before aborting
function abortIfRunning(pp: ProcessPromise): void {
  if (pp.stage === 'running') pp.abort()
  else setImmediate(() => pp.stage === 'running' && pp.abort())
}

try {
  pp.abort()
} catch (e) {
  if (e instanceof Fail && /without creating one/.test(e.message)) {
    pp.run() // for halted promises
    pp.abort()
  } else throw e
}

When it happens

Trigger: Calling abort() on a halted ProcessPromise (`$({halt:true})`) before .run() is invoked; aborting synchronously in the same tick as `$` creation before the spawn microtask runs; aborting a command that was never run.

Common situations: Halted pipelines where run() is deferred; abort wired to synchronous setup code; deferred command graphs that abort before launch.

Related errors

• Trying to kill a process without creating one.
• Too late to abort the process.
• The signal is controlled by another process.
• Too late to kill the process.
• Cannot pipe to a settled process.

AI-assisted analysis of google/zx@00a2c484e2 (2026-08-13). Data as JSON: /api/errors/b5be4476bf7007f8. Report an issue: GitHub.