Ubuntu – Unable to set Chrome as the default browser; what else can I try

I have done everything I can to set Google Chrome as my default browser in Ubuntu 12.04, but absolutely nothing seems to work. Anything new I could try would be greatly appreciated.

Whenever I open Chrome, Chrome displays the message 'Chrome is not the default browser' with the button 'Set as default as browser'. This message does not disappear. I also cannot install extensions in Chrome, which always returns the following error:

Could not install package: 'UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL'.
Could not install package because a utility process crashed.
Try restarting Chrome and trying again.

I read somewhere (I forgot where unfortunately) that this error is related to the error of refusing to be the default browser.

Additionally, when I open Chrome from the command line, it opens successfully but I do get an error message:

$ google-chrome-stable
LaunchProcess: failed to execvp:
/proc/self/exe

So here the list of things I already tried:

== Things I tried ==

Simple things

• System Settings -> Details -> Default Applications

  Chrome is set correctly here as the default browser, but I still get the error messages.

• Use the 'Make Google Chrome the default browser' button in the Chrome settings. This button does nothing when I click it. It's not disabled, it just does nothing.
• Reinstalling Chrome.
• Setting $BROWSER – this variable was empty by default and setting it to google-chrome did not help.

mimeapps.list

I edited ~/.local/share/applications/mimeapps.list, and it currently looks like this:

[Added Associations]
application/x-executable=gedit.desktop;
image/png=eog.desktop;
x-scheme-handler/http=google-chrome.desktop;
x-scheme-handler/https=google-chrome.desktop;
image/svg+xml=inkscape.desktop;
application/pdf=inkscape.desktop;

[Default Applications]
x-scheme-handler/http=google-chrome.desktop
x-scheme-handler/https=google-chrome.desktop
image/svg+xml=inkscape.desktop
text/html=google-chrome.desktop
x-scheme-handler/http=google-chrome.desktop
x-scheme-handler/https=google-chrome.desktop
x-scheme-handler/about=google-chrome.desktop
x-scheme-handler/unknown=google-chrome.desktop

This doesn't solve the problem.

defaults.list

I removed all mentions of 'firefox' in ~/.local/share/applications/defaults.list. Everything seems to be set correctly to google-chrome.desktop, but I still get the error message.

xdg-settings

sudo update-alternatives --config x-www-browser

returns the following:

There are 2 choices for the alternative x-www-browser (providing /usr/bin/x-www-browser).

  Selection    Path                           Priority   Status
------------------------------------------------------------
* 0            /usr/bin/google-chrome-stable   200       auto mode
  1            /usr/bin/firefox                40        manual mode
  2            /usr/bin/google-chrome-stable   200       manual mode

Switching between these options did nothing.