eventLoopBlockIntegration doesn't detect main process hangs

[nikitakot]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Self-hosted/on-premise

Electron SDK Version

7.2.0

Electron Version

36.9.5

What platform are you using?

Windows

Link to Sentry event

No response

Steps to Reproduce

See gist - https://gist.github.com/nikitakot/5f6e7e111ddd77dc74d5166a3e56e4af

1. $ npm i
2. $ npx electron-rebuild
3. $ npm start

The app will get hang as expected because of the blocking sync operation:

setTimeout(() => {
  console.log("Simulating event loop block in main process...");
  execSync("ping -n 5000 -w 1000 localhost > nul");
  console.log("Event loop block completed");
}, 5000);

But the eventLoopBlock is not triggered.

Expected Result

eventLoopBlock is triggered.

Actual Result

eventLoopBlock is not triggered.

[linear]

ELECTR-34

[timfish]

I don't know what platform you are on but I couldn't get your ping command to work.

When I used the following on macOS:

spawnSync('ping localhost', { shell: true, timeout: 10000 });

It captured an event with the expected stack frames:

                  {
                    function: '?',
                    filename: 'app:///src/main.mjs',
                    lineno: 32,
                    colno: 5,
                    in_app: true
                  },
                  {
                    function: 'longWork',
                    filename: 'app:///src/main.mjs',
                    lineno: 26,
                    colno: 3,
                    in_app: true
                  },
                  {
                    function: 'spawnSync',
                    filename: 'node:child_process',
                    lineno: 884,
                    colno: 24,
                    in_app: false
                  },
                  {
                    function: 'spawnSync',
                    filename: 'node:internal/child_process',
                    lineno: 1120,
                    colno: 20,
                    in_app: false
                  },

[nikitakot]

@timfish I'm on Windows 11, can you give a try on Windows too?

Also how can I try to disable uploading the events and what folder should I check to exclude issues with our own Sentry instance? Like locally offline debug the sdk.

Thanks.

[timfish]

This captures events in CI on all three platforms:
https://github.com/getsentry/sentry-electron/pull/1253/files#diff-36e6cd764896407f6f6836936bae915a737ff555a63c8af3a7987ac6f3f06654R24