"CRITICAL: We failed, but the fail whale is dead. Sorry..."

Question

When I started up my machine today I got some quite bizarre messages in my syslog:

...
Aug 17 18:58:15 Floral-Towel systemd[1349]: Startup finished in 266ms.
Aug 17 18:58:15 Floral-Towel systemd[1349]: Starting Default.
Aug 17 18:58:15 Floral-Towel systemd[1]: Started User Manager for UID 121.
Aug 17 18:58:15 Floral-Towel freshclam[782]: Empty script safebrowsing-43732.cdiff, need to download entire database
Aug 17 18:58:17 Floral-Towel gnome-session[1355]: gnome-session[1355]: CRITICAL: We failed, but the fail whale is dead. Sorry....
Aug 17 18:58:17 Floral-Towel gnome-session[1355]: CRITICAL: We failed, but the fail whale is dead. Sorry....
Aug 17 18:58:17 Floral-Towel gdm[1232]: Child process -1352 was already dead.
Aug 17 18:58:17 Floral-Towel systemd[1]: Stopping User Manager for UID 121...
Aug 17 18:58:17 Floral-Towel systemd[1349]: Stopped target Default.
Aug 17 18:58:17 Floral-Towel systemd[1349]: Stopping Default.
Aug 17 18:58:17 Floral-Towel systemd[1349]: Stopped target Basic System.
...

I included some of the other messages around that time just in case if they might be of help in some way. But to get to the point, who, or what, is "the fail whale"? And why is he/she/it dead? What is the meaning of all this? And what's it doing in my syslog?

I am running Ubuntu Gnome 15.04, with Gnome Shell, and Gnome 3.16.

---

OS Information:

No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 15.04
Release:    15.04
Codename:   vivid

Package Information:

gnome-session:
  Installed: 3.16.0-0ubuntu1~vivid1
  Candidate: 3.16.0-0ubuntu1~vivid1
  Version table:
 *** 3.16.0-0ubuntu1~vivid1 0
        500 http://ppa.launchpad.net/gnome3-team/gnome3-staging/ubuntu/ vivid/main amd64 Packages
        100 /var/lib/dpkg/status
     3.14.0-2ubuntu5 0
        500 http://gb.archive.ubuntu.com/ubuntu/ vivid-updates/main amd64 Packages
     3.14.0-2ubuntu4 0
        500 http://gb.archive.ubuntu.com/ubuntu/ vivid/main amd64 Packages
     3.14.0-2ubuntu4~vivid1 0
        500 http://ppa.launchpad.net/gnome3-team/gnome3/ubuntu/ vivid/main amd64 Packages

Solution

In this case the "fail whale" is an error message logged by GNOME if something went wrong. It's named after a illustration by Yiying Lu used by Twitter to display errors.

If it is dead it means that there's not enough of GNOME running to display the error.

Comments

[Hans Deragon]

The link to the illustration by Yiying Lu does not work anymore.

[Yeppii]

@HansDeragon It works!