Feature Freeze Exception: Seeding the official Firefox snap in Ubuntu Desktop

$ snap info firefox|grep installed
installed:          92.0-3                  (595) 159MB -
$ apt-cache show firefox | grep Installed
Installed-Size: 221407

the installed firefox snap is exactly 60MB smaller than the installed deb …

note that snap packages (unlike debs) do not get unpacked but only bind-mounted (as compressed, gpg signed (and thus tinker proof) readonly filesystem images)…

snaps are typically significantly smaller than what you get when installing the equivalent content on disk from debs.


Just out of curiosity: How do you install the Firefox deb without using disk space?

Problem with google earth can easily be reproduced with samples in https://www.khronos.org/webgl/wiki/Demo_Repository
occurs only in Wayland session but DOES NOT OCCUR with X11 session.


It is the snap updates , leaves snap never self removed. Unless I missed a auto remove of the snap processing. over time the snap builds up.

snap packages have a builtin rollback mechanism as well as a builtin self-test mechanism …

i.e. if an apache snap is updated you can define that it checks for port 80 to be open after an upgrade … if that test fails, it will automatically roll back to the last known good version on disk to guarantee operation of the app/service (though admittedly desktop snaps do not use that feature a lot)) …

along with that, if your firefox snap is released with a bug or a new feature is broken you can always manualy do snap revert firefox

for this feature the last good snap as well as the current snap are always kept around …

you can define the number of snaps to keep with sudo snap set system refresh.retain=2 (2 is the minimum here) as documented in:

while this indeed means you always have the same snap installed two times, the snap compression usually compensates this … while they do occupy more disk space, it is usually not a lot more than their unpacked equivalent in deb or rpm …


Did you consider spellchecking in other languages than English (US)?

I made a Swedish install from the latest daily build. As expected the Swedish dictionary for spellchecking is present at first login in /usr/share/hunspell and can be used directly by several common programs. Confirmed with LibreOffice Writer and gedit. And if Firefox had been installed as an APT package, Swedish spellchecking would have worked out of the box in Firefox too.

But in the Fixefox snap only English (US) spellchecking is available to start with. I suppose the reason is that the snap does not see /usr/share/hunspell.

I can download and install Swedish spellchecking from Mozilla as an extension. If I do, it ends up as a compiled .xpi file in my Firefox profile in the ~/snap/ directory. (And it’s actually the same dictionary as I already have in /usr/share/hunspell.)

Nevertheless, the need to figure out how to do that is an unfortunate regression in my opinion. Ubuntu users expect spellchecking to work out of the box also in Firefox. So it would be highly desirable if the AppArmor profile could be modified so also the Firefox snap sees and can make use of the dictionaries in /usr/share/hunspell.


I think one way to improve the situation is what I have proposed here https://forum.snapcraft.io/t/proposal-use-casync-for-delta-updates/26277 – i.e. instead of keeping the whole snap of the old revisions, only keep the delta, that can be used to reconstruct the old revision from the latest install snap as the “seed”. It helps both the IoT case as well as the Desktop case.


Hey Gunnar, spellchecking has been discussed there before https://forum.snapcraft.io/t/desktop-allow-access-to-host-hunspell-dictionaries , it doesn’t seem to be resolved at the time though and isn’t as easy as granting access to one directory

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On my Ubuntu 21.10 some time ago i installed firefox snap and then removed it. Now with the updates i don’t see FF snap reinstalled. Should i reinstall ‘by hand’?

The snap will be installed automatically in the following scenarii:

  • installing a fresh 21.10 from a recent ISO
  • dist-upgrading from 21.04

If you dist-upgraded some time ago, the change wasn’t in place yet, so yes, you’ll need to re-install the snap manually (if that’s what you want to use, otherwise the deb remains available and supported).

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Thanks for the feedback @laney!

Your issue with cursors is very likely https://gitlab.gnome.org/Community/Ubuntu/gnome-sdk/-/issues/6.

For any issue that didn’t fix itself automagically and which you can still reproduce, bug reports are welcome on the upstream tracker (make sure to mention “snap” in the bug title for easier triaging). I’m personally triaging and investigating all of them.


Thanks, in fact on my Ubuntu 21.10 installed from Beta I found FF snap and manually installed FF deb to compare, while on my Ubuntu 21.10 installed from an older ISO i see only FF deb.
Thanks again.

Four years ago… But now maybe the most important desktop application — Firefox — will be provided as a snap, and spellchecking is an important aspect of the typing experience. I can just say: Please give this issue some priority. It would be sad if it would still be present at the 22.04 release.


You’re right Gunnar. Strictly speaking, this is a functional regression, so that’s not looking good.

I filed upstream bug 1732755 to keep track of it. As has already been discussed in the past, there’s no obvious and easy to implement solution, but we’ll work something out. Suggestions welcome.


filed https://bugzilla.mozilla.org/show_bug.cgi?id=1732815 upstream to track the screen sharing issue

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This spellchecker thing should be a no-go according to me…
Almost everything I write is through my web browser, and I am changing languages several times a day, I really need this feature. Half the Europeans use several languages in their daily life.


this is one of the reasons why the deb will still be around for the next release, so things can be sorted before the LTS …


While we acknowledged the problem and I agree this is not as convenient as using the host’s hunspell dictionaries, please note that you can install spellchecking dictionaries in firefox from about:addons, which works around the problem.


Clicking links in Evince to open them in Firefox does not work:

$ evince
env: ‘/snap/bin/firefox’: Permission denied

see also the Apparmor denial

= AppArmor =
Time: Oct  1 11:37:16
Log: apparmor="DENIED" operation="exec" profile="/usr/bin/evince" name="/usr/bin/snap" pid=20253 comm="env" requested_mask="x" denied_mask="x" fsuid=1001 ouid=0
File: /usr/bin/snap (exec)
* adjust snap to ship 'snap'
* adjust program to use relative paths if the snap already ships 'snap'

So it’s rather a problem with the apparmor browser abstraction file (/etc/apparmor.d/abstractions/ubuntu-browsers), but something that needs to be resolved nonetheless.


more likely a missing entry in /etc/apparmor.d/abstractions/evince to allow execution access to /usr/bin/snap … but that will need input and review by the security team i guess …