consuming spawn UV_EACCES errors

[TrevTheDev]

• Node.js Version: 11.9.0
• OS: linux
• Scope (install, code, runtime, meta, other?):
• Module (and version) (if relevant):child_process.js

How should one consume UV_EACCES errors raised using spawn?

Assuming code like this:

const { spawn } = require('child_process');
const ls = spawn('ls', ['-lh', '/usr'],{cwd: '/dir/that/has/permissions/set/to666});

//next line throws an error because stdout does not exist due to UV_EACCES  error:
ls.stdout.on('data', (data) => {
  console.log(`stdout: ${data}`);
});

ls has an error event, but how should I access this before ls.stdout throws an error?

[gireeshpunathil]

the way I understand spawn logic is: treat any errors that occur upto fork / clone system call within the parent, and synchronously, while anything after that, handle as an error event on the child process, asynchronously. When checked with strace, I see the UV_ACCESS is occurring once the child has started execution, so I would expect it to emit an error event, deeming it as a runtime error - I guess that is not happening here. Pinging @nodejs/child_process to see if there is an explanation to this behavior.

[cjihrig]

I believe nodejs/node#26852 is tracking this same issue.

[gireeshpunathil]

@TrevTheDev - nodejs/node#27696 is merged into node, does it solve your issue?

[gireeshpunathil]

answered, closing