cannot catch ENOENT when non-node spawn is missing

[jdmairs]

So I'm using forever-monitor to spawn a c++ executable. It works great. I then purposefully delete the executable to test my error handling in Express.

export async function startProcess(): Promise<void> {
  return new Promise((resolve, reject) => {
    const child = forever.start(['./Foo'], {
      max: 1,
    });
    child.on('exit', () => {
      getLogger('NewJobNanny').info('Foo has exited gracefully');
      resolve();
    });

    child.on('stdout', (data: any) => {
      getLogger('NewJobNanny').info('Detecting stdout ', data);
    });

    child.on('error', (error) => {
      getLogger('NewJobNanny').error('startProcess detected error: ', error);
      reject(error);
    });
  });

I have a catch on startProcess but it does not catch. Instead my node/express app crashes with the following

events.js:200
throw er; // Unhandled 'error' event
^

Error: spawn ./Foo ENOENT
at Process.ChildProcess._handle.onexit (internal/child_process.js:264:19)
at onErrorNT (internal/child_process.js:456:16)
at processTicksAndRejections (internal/process/task_queues.js:81:21)
Emitted 'error' event on ChildProcess instance at:
at Process.ChildProcess._handle.onexit (internal/child_process.js:270:12)
at onErrorNT (internal/child_process.js:456:16)
at processTicksAndRejections (internal/process/task_queues.js:81:21) {
errno: 'ENOENT',
code: 'ENOENT',
syscall: 'spawn ./Foo',
path: './Foo',
spawnargs: []
}