If Ungoogled Chromium ver 112 is running when Nheko is launched, the
UC job freezes. No user i/o is accepted.. it becomes like a kind of
software brick. UC cannot even be closed, only killed from the CLI.

If UC is left alone in the frozen state until Nheko exits, then Nheko
brings UC down with it.

This report is tagged as /critical/ because it disasterously impacts
another unrelated application. It’s also a local security problem
because different X or Wayland apps should not have the capability of
interfering with each other like this. But I did not tag the report as
“security” because it’s not the sort of vuln that remote attackers
could easily exploit without chaining other exploits.

FWIW, the testing was done on a system running Wayland, Sway, and X
Wayland.

Also note that Ungoogled Chromium is not in official Debian repos. But
Chromium is, so this defect likely impacts Chromium. I have not tested
that myself but if someone confirms it, then this bug should be tagged
as affecting Chromium.

Quoting Manny (2025-10-10 15:53:46)

Thanks for reporting this issue.

From your description, it seems to me that Ungoogled Chromium might
just as well be the cause of the fatal situation you describe.

Also, Debian cannot meaningfully extend its stability to cover
non-Debian code that we cannot possibly examine let alone fix.

For these reasons, I am lowering the severity.

 - Jonas

I just did a quick test on a OnePlus 6 phone running Debian/Testing with
chromium 144.0.7559.96-1 and nheko 0.12.1+~0.10.1+~1.0.0+~0.3.1-2+b1 and they
seem to work together OK.

Where did you get ungoogled chromium from?  Is someone running an apt
repository for it?

As an aside I've got a build/test server with 44 cores I can share with anyone
who needs to rebuild chromium and doesn't have enough local CPU power.