Sometimes the UI does not show up when starting the browser. However, the browser is still interactable, like the window title changes when I press "Ctrl-W", or the pop-up menu opens when I click on the tab bar.

In my case, this behavior first shows up in about Oct 19.

Logs when the window does not show:

ATTENTION: default value of option mesa_glthread overridden by environment.
ATTENTION: default value of option mesa_glthread overridden by environment.
ATTENTION: default value of option mesa_glthread overridden by environment.
ATTENTION: default value of option mesa_glthread overridden by environment.
(...)
###!!! [Parent][RunMessage] Error: Channel closing: too late to send/recv, messages will be lost

Logs when the window shows:

ATTENTION: default value of option mesa_glthread overridden by environment.
ATTENTION: default value of option mesa_glthread overridden by environment.
ATTENTION: default value of option mesa_glthread overridden by environment.
ATTENTION: default value of option mesa_glthread overridden by environment.
[GFX1-]: Failed to create EGLContext!: 0x3001
ATTENTION: default value of option mesa_glthread overridden by environment.
(...)
###!!! [Parent][RunMessage] Error: Channel closing: too late to send/recv, messages will be lost

Since I see lines of mesa or GFX stuffs, it might lie in the Core::Graphics category.

Thanks for the report! Please open about:support, click on "Copy text to clipboard" and paste it here.

(In reply to Darkspirit from comment #1)

Thanks for the report! Please open about:support, click on "Copy text to clipboard" and paste it here.

Hi, it's attached here.

Thanks for the report! While I think this must be an odd setup problem*, we really should fall back so software rendering here. Will look into it!

*we only try to create a GL context if it previously worked in the glxtest smoke test and you say it only happens sometimes - sounds to me like the setup/driver is flaky, which it should not be :/

Hm this is very mysterious. I tried artificially reproducing this issue but things always fell back to something reasonable. It would be great to have this confirmed by more people/reports, because right now I really don't know if that's a bug on our side.

It looks like the EGL window is not connected to XWindow. It may happen when a window is mapped/unmapped, GdkWindow stays the same but underlying XWindow is changed. In such case we don't regenerate the EGL window. I'll try to finish Bug 1730533 asap as it solves such cases.

Also note that the XWindow change while map/unmap is a bit random - it usually stays the same but it can change.

(In reply to Martin Stránský [:stransky] (ni? me) from comment #5)

I'll try to finish Bug 1730533 asap as it solves such cases.

Okay. I see it has landed. I'll let you know if the problem persists (or not).

Hi, with the version 95.0a1 (2021-10-28), I can see that the problem does not resolve. The logs when it can (or cannot) open is the same as mentioned in the head of this bug.

I haven't seen it reproduce in the last 3 days since I replied Comment 8. This bug is probably resolved... but since it doesn't have a stable STR, I can't fully sure it's fixed though.

May be related to Bug 1738026

(In reply to Outvi V from comment #2)

GPU #2
Active: No
Vendor ID: 0x10de
Device ID: 0x1c8c

Do you have the proprietary Nvidia driver installed?
There is a libglvnd bug (bug 1731480).

I saw this bug with Nightly (2021-10-31), but didn't have luck to reproduce it with patch from bug 1731172 comment 24.

Without the patch:
(Darkspirit from bug 1731172 comment 35)

At one time, Firefox was transparent and there were many "Error in eglSetDamageRegion: 0x3001" (EGL_NOT_INITIALIZED) in the terminal.

With the patch: partial present bug

Do you have the proprietary Nvidia driver installed?
There is a libglvnd bug (bug 1731480).

Yes.

Also I want to mention that (due to some considerations) I asked bbswitch to turn off NVIDIA module on boot (via optimus-manager) days later, so that may also be the recent I haven't come across this bug recently. I'll continue testing for a few days to see if the bug still occurs on my device.

The severity field is not set for this bug.
:jimm, could you have a look please?

For more information, please visit auto_nag documentation.

(In reply to Outvi V from comment #12)

Do you have the proprietary Nvidia driver installed?
There is a libglvnd bug (bug 1731480).

Yes.

Also I want to mention that (due to some considerations) I asked bbswitch to turn off NVIDIA module on boot (via optimus-manager) days later, so that may also be the recent I haven't come across this bug recently. I'll continue testing for a few days to see if the bug still occurs on my device.

Please try to revert your changes to check if this bug still occurs. (bug 1740675)

(In reply to Darkspirit from comment #14)

Please try to revert your changes to check if this bug still occurs. (bug 1740675)

Okay. I've uninstalled bbswitch recently, and I'll let you know whether I'm reproducing this in recent days.

(In reply to Darkspirit from comment #14)

Please try to revert your changes to check if this bug still occurs. (bug 1740675)

Hi. For the two weeks I haven't experienced this problem. Probably this bug has been fixed.

Closing per Comment 16