Comment 123 for bug 1197395

Here's a scenario where this freezes the desktop entirely:

- Open a Cinnamon session
- Open nemo
- Right-click a directory and select "Open as Administrator"
- Wait a few minutes

The entire desktop freezes.

You can tail -f your .xsession-errors to see that the two nemo (the one run by cinnamon-session as you, and the one run as root via pkexec) collide with the same runtime directory (/run/user/1000). The root nemo is using dconf which creates a root:root rw------- dfonf/user file in /run/user/1000.

While that file exists, any application using dconf can either crash or freeze, as dconf is unable to function correctly. What usually happens in Cinnamon is that cinnamon-settings-daemon is the first to freeze.

In this example I used nemo and cinnamon, but this would happen with any other components using dconf, or even glib, or XDG_RUNTIME_DIR directly (like pulseaudio).

What we're doing at the moment is switching nemo to use gksu instead of pkexec... and we're considering patching glib to stop using XDG_RUNTIME_DIR entirely.

Of course glib is doing what it should, and so is pkexec.. and according to upstream so is systemd, but as you can see there's absolutely no way we can ship with a bug that critical. Apps cannot use the same runtime path when they are elevated with admin permissions, because they create files which permissions prevent other apps to access thus generating crashes and freezes.

This problem is brand new in Ubuntu. I understand that from a design point of view there might be issues with su and all, but we did not face random loss of pa servers, DE freezes and app crashes like we're facing now.

Again, I've no opinion as to which components should adapt here, but there is a clear issue and a huge impact on the users.