"Cannot add sidebar form if sidebar is not visible" error while sidebar is showing

[twschiller]

Describe the bug

• "Cannot add sidebar form if sidebar is not visible" error while sidebar is showing
• The form brick is being shown from a custom trigger

To Reproduce

Steps to reproduce the behavior:

1. Activate the page canvas mod
2. Click on "+ Create"

Actual behavior

An error is show, the form is show, but you can't submit the form

It's happening 100% of the time for @MMirandi? I've been seeing it sporadically

Expected behavior

No error is shown, form is shown and you can submit it

Screenshots/Loom

https://pixiebrix.slack.com/archives/C07DJTPAAHG/p1723830246189949

[twschiller]

I also experienced this when creating an announcement in the announcements mod this morning

[fungairino]

I saw this error pop up the first time I tried creating a canvas, but I have not been able to replicate in any other subsequent tests.

I reached out to @MMirandi to see if I can observe this happening on his machine.

[fungairino]

It seems like no one can reproduce this consistently any more. Taking a look at the code execution paths, it seems like we should emit the error to datadog if this happens, but I didn't see any instances of it in the production environment.

I don't see any obvious places to add additional error handling or error logging, so overall I'm inclined to shelve this issue. If this pops up again we can take another look.

[twschiller]

Taking a look at the code execution paths, it seems like we should emit the error to datadog if this happens, but I didn't see any instances of it in the production environment.

Can you try always throwing the exception and see if it hits Datadog? And if not, see where/why the error is getting swallowed?

so overall I'm inclined to shelve this issue. If this pops up again we can take another look.

I'll spend some cycles today trying to reproduce while working on welcome mods today

[fungairino]

Can you try always throwing the exception and see if it hits Datadog? And if not, see where/why the error is getting swallowed?

Yes, I did. If the "Cannot add sidebar form if sidebar is not visible" error is forced to be thrown in the same place, it is logged to Datadog. So it seems like there could be some intermittent issue with the messenger, or the logs failed to be emitted.

[twschiller]

Reliable reproduction for me: https://www.loom.com/share/8e0f1e67634741568f87b22da50b0b7d?from_recorder=1&focus_title=1

Useful for reproducing, but might not be something we need to fix because it's a corner case

[fungairino]

Todd and I did a quick troubleshooting session on this.

• Todd can almost consistently replicate this issue on his browser following the steps in his loom
  • I tried repeatedly to replicate using the same version, and method, but I never ran into this error.
• We confirmed that when this happens, we log expected telemetry to datadog and our backend errors.
• Right now only internal users have run into this error (Mike, Todd and Britt) - about 20ish errors so far.

Given that this error occurs in very edge-case scenarios, and is hard to reproduce consistently we will pause on continuing to troubleshoot this and monitor to see how often this issue occurs.