COSMIC Desktop and Flatpaks

Carly · 2026-02-23 06:25:21

Hi everyone,

I hope this is the right place to share some feedback.

I’m using the COSMIC desktop and ran into issues with Firefox from Flathub. Right-click context menus were not appearing, and about:config was not rendering properly.

I believe I may have identified the cause. After installing COSMIC, only the xdg-desktop-portal-cosmic portal was running. However, Flatpak applications seem to have issues with it. After installing xdg-desktop-portal-gtk, everything started working correctly.

I can’t pinpoint the exact root cause, but it seems that the COSMIC portal may not yet be fully ready for production use.

Perhaps the COSMIC package in the extra repository could include the GTK portal by default to avoid such issues for users?

All the best from Vienna, Austria,
Carly

seth · 2026-02-23 08:45:00

Right-click context menus were not appearing, and about:config was not rendering properly

That's extremely unlikely to be portal related.
co·inki·dink?

Carly · 2026-02-24 18:20:49

Well, I just uninstalled xdg-desktop-portal-gtk, rebooted and Firefox is broken. After re-installing xdg-desktop-portal-gtk it works again. What can I say...

Carly · 2026-02-24 18:24:38

Well, I just uninstalled xdg-desktop-portal-gtk, rebooted and Firefox is broken. After re-installing xdg-desktop-portal-gtk it works again. What can I say...

seth · 2026-02-24 21:22:41

Broken "how"?
The xdg-desktop-portal implementation is relevant to desktop integration (the opens/save/print dialogs) but the idea that it relates to browser rendering issues or the internal popup menu (FF doesn't even use gtk for any of that) is implausible.

Are there portal related errors in your journal?
Did/does xdg-desktop-portal-gtk draw in other dependencies?
Does it have impact on whether FF uses wayland or X11/xwayland?
https://wiki.archlinux.org/title/Waylan … plications

qinohe · 2026-02-24 22:27:26

@seth, OP is using FF flatpak which depends on xdg-desktop-portal, which depends on xdg-desktop-portal-impl(.....)

seth · 2026-02-24 22:43:52

Yes, but the OP also has https://archlinux.org/packages/extra/x8 … al-cosmic/ and I struggle to see how portal specifically would be involved in FF rendering a webpage.
Though there's indeed https://github.com/pop-os/xdg-desktop-p … issues/262

https://github.com/pop-os/xdg-desktop-p … poch-1.0.3 isn't much, though, but if https://archive.archlinux.org/packages/ … kg.tar.zst indeed still works you might be running into the abort and that might break some DPI value?

qinohe · 2026-02-24 23:15:26

Agreed, I follow your logic on the Issue '262' and the xdg-desktop-portal-cosmic should render a correct working flatpak FF indeed.
The breaking DPI part is somewhat above my pay-grade, though I get the picture , thanks

Carly · 2026-02-25 08:14:57

Thanks, seth for pointing me to the GitHub issue. I don't know my way around on Git yet and would probably not have found it on my own. I have left a short comment there, hoping it may be of use.

Not sure how things work on this forum, but I think this thread can be closed.

seth · 2026-02-25 08:20:31

Can you test whether the "previous" https://archive.archlinux.org/packages/ … kg.tar.zst also causes this and you should probably check whether you're getting the "zwp_linux_dmabuf_v1 not available on this compositor" error.
The change seems deliberate and might hint at a wider issue (broken graphics stack), in doubt please post your complete system journal for the boot:

sudo journalctl -b | curl -F 'file=@-' 0x0.st

Arch Linux

#1 2026-02-23 06:25:21

COSMIC Desktop and Flatpaks

#2 2026-02-23 08:45:00

Re: COSMIC Desktop and Flatpaks

#3 2026-02-24 18:20:49

Re: COSMIC Desktop and Flatpaks

#4 2026-02-24 18:24:38

Re: COSMIC Desktop and Flatpaks

#5 2026-02-24 21:22:41

Re: COSMIC Desktop and Flatpaks

#6 2026-02-24 22:27:26

Re: COSMIC Desktop and Flatpaks

#7 2026-02-24 22:43:52

Re: COSMIC Desktop and Flatpaks

#8 2026-02-24 23:15:26

Re: COSMIC Desktop and Flatpaks

#9 2026-02-25 08:14:57

Re: COSMIC Desktop and Flatpaks

#10 2026-02-25 08:20:31

Re: COSMIC Desktop and Flatpaks

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