Getting fstat error since latest release when running JS code on Windows

[johnridesabike]

I recently started getting test failures on a Github Actions job using Windows and JSOO-generated code. I don't have a Windows machine directly available, so I apologize for being unable to provide a minimal reproducible example.

The exact error is this (link):

node:fs:1644
  handleErrorFromBinding(ctx);
  ^

Error: EINVAL: invalid argument, fstat
    at Object.fstatSync (node:fs:1644:3)
    at new AB (D:\a\acutis\acutis\_build\.sandbox\e437599ddd7afc5fce4ce1a65f7b45e0\default\main.cjs:661:12)
    at XO (D:\a\acutis\acutis\_build\.sandbox\e437599ddd7afc5fce4ce1a65f7b45e0\default\main.cjs:852:29)
    at y9 (D:\a\acutis\acutis\_build\.sandbox\e437599ddd7afc5fce4ce1a65f7b45e0\default\main.cjs:880:21)
    at D:\a\acutis\acutis\_build\.sandbox\e437599ddd7afc5fce4ce1a65f7b45e0\default\main.cjs:881:14
    at D:\a\acutis\acutis\_build\.sandbox\e437599ddd7afc5fce4ce1a65f7b45e0\default\main.cjs:881:202
    at Object.<anonymous> (D:\a\acutis\acutis\_build\.sandbox\e437599ddd7afc5fce4ce1a65f7b45e0\default\main.cjs:4927:119)
    at Module._compile (node:internal/modules/cjs/loader:1364:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1422:10)
    at Module.load (node:internal/modules/cjs/loader:1203:32) {
  fd: 0,
  errno: -4071,
  syscall: 'fstat',
  code: 'EINVAL'
 }

Node.js v18.20.6

The line number in the error message seems to point to this code from the JSOO runtime source:

js_of_ocaml/runtime/js/fs_node.js

Line 332 in 937e849

var stats = this.fs.fstatSync(fd);

Some notes:

• I don't believe the JSOO program in my tests calls any IO functions directly.
• I didn't modify anything in the test before the test started breaking (the only commits were non-code).
• This does not happen on MacOS or Linux tests.

[vouillon]

Thanks a lot for your bug report.
This is certainly due to commit 1d7f690. It seems stdout and/or stderr are not available or are misdetected by node/libuv. I think we should just catch the exception and ignore it.

[hhugo]

We should try to reproduce the issue in our CI and add a regression test

[hhugo]

It seems that the issue is with node 18, could you try with version 20 or above ?

[johnridesabike]

Using the LTS version seems to have fixed the problem. Thanks for looking into it!