Many Gnome extensions don't work with gnome-shell in 17.10, but works in vanilla gnome

[Jesse]

There are multiple GNOME extensions that work in the vanilla gnome session (package gnome-session) in 17.10, but when you run the gnome-shell with Ubuntu modifications, the extensions give errors and won't load.

Here are four examples of extensions that don't work with the Ubuntu-modified GNOME shell:

https://extensions.gnome.org/extension/2/move-clock/
https://extensions.gnome.org/extension/358/activities-configurator/

Those extensions were believed to be broken due to Ubuntu session on GNOME Shell, but are broken in the vanilla gnome session as well (due to 3.26 changes):
https://extensions.gnome.org/extension/298/activities-button-text/
https://extensions.gnome.org/extension/77/activities-button-text/

Bug discovered using:
Ubuntu 17.10 beta 2
GNOME Shell 3.26.0 (Xorg or Wayland session)
Linux kernel 4.13.0-12-generic

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Daniel van Vugt (vanvugt)]

Confirmed. Looks like this might be caused by the hard-coded Ambiance theme in the panel.

[Didier Roche-Tolomelli (didrocks)]

I don't know how the harcoded Ambiance theme compared to the gnome.css one can influence that. Do you mind expanding if you already had a start debugging Daniel?

[Daniel van Vugt (vanvugt)]

That was an overstatement; I'm just guessing. Not working on it.

[Didier Roche-Tolomelli (didrocks)]

Here is some analyze of those extension:

* move clock doesn't work due to those lines:
    // do nothing if we're not in user mode
    if ( Main.sessionMode.currentMode != 'user' ) {
        return;
    }

To allow people using the upstream vanilla session, we have an ubuntu mode, inheriting from the user one. However, the mode name is different. Different fixes:
-> you can poke move clock upstream to use a blacklist isn't of a whitelist (disabling under kiosk and gdm mode for instance)
-> you can ask on gnome bugzilla for the shell to expose the inheritance hierarchy to extensions, and they can check if they are in the user mode that way. Then extensions will need to be updated as well.

* Activities Configurator doesn't work because it relies on the hot corner that we disable in the ubuntu session. I think poking upstream to get that optional would help (especially as there is some chance to have that configurable upstream, we took an upstream patch not committed yet).

* Activites button text (both extensions) don't work either on a vanilla GNOME session. The name property as changed in GNOME Shell 3.25.9x, and so, the code needs to be updated. This isn't related to the ubuntu session.

So, in summary:
Only "move clock" and "activities configurator" don't work in the ubuntu session only, but both has to be upstream extension fixes. If someone wants to poke the upstream extension maintainer and point them to this thread, that would be great.
The 2 other "activities button text" extensions are broken in GNOME Shell 3.26, in both sessions, and not related to any ubuntu change. Upstream needs to update their extensions to work with the new GNOME Shell version.

[Daniel van Vugt (vanvugt)]

Are extensions able to test if currentMode inherits from 'user'? If so then that would be a fix. If not then it sounds like mode 'ubuntu' is going to be a recurring problem in future.

[Jesse (jessedubord)]

In this morning's test of 17.10 beta 2, this extension now works:

https://extensions.gnome.org/extension/2/move-clock/

The rest still don't seem to work. Just an update. :)

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 17.10 (artful) reached end-of-life on July 19, 2018.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed.