Failed to create sharedmemoryfile /WK2SharedMemory.XXXXXXXX: Permission denied

[Benjamin Tegge]

Observed behaviour: the Ubuntu installer slows down to a crawl at the stage of restoring previously installed packages.

The following message is displayed in the installers terminal view: Failed to create sharedmemoryfile /WK2SharedMemory.XXXXXXXX: Permission denied

Steps to reproduce:

1. Have an already installed version of 14.04 or 16.04
2. Start the Ubuntu 16.04(.1) installer from desktop installation media
3. Choose to do "something else" instead of installing over or alongside and choose the previous root partition for the new root partition but _don't_ format it.
4. Continue with the installation as usual.
5. Open a terminal and run `top` to monitor the CPU load, at the stage of "restoring previously installed packages" a WebKitWebProcess shows up consuming almost 100% of CPU resources. After Killing it with `killall WebKitWebProcess` the installation continues.

This has been reproducible on al laptop for 14.04 and 16.04 as well as VirtualBox VMs with 14.04 and 16.04 preinstalled. Installing a package like lyx (pulls in tex dependencies and many megabytes of data) might help triggering this bug but I also encountered it without lyx preinstalled during tests.

Bugs found with related error messages: https://bugs.webkit.org/show_bug.cgi?id=134892

Users on AskUbuntu reporting this issue: http://askubuntu.com/q/761930/40581

[Benjamin Tegge (livewirebt)]

This is the debug log file from /var/log/installer stripped of "Failed to create sharedmemoryfile /WK2SharedMemory.XXXXXXXX: Permission denied" with grep -v. The entire file is 2 GB in size and still 126 MB when compressed with xz -9, I can upload it, but I thought this would be wasting Launchpad's resources.

[Launchpad Janitor (janitor)]

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

[Tommy Trussell (tommy-trussell)]

I presume the WebKitWebProcess puts the slide show on the installer window? I noticed the slide show became nonfunctional after the "Failed ..." messages started appearing in the terminal area. Killing off the process apparently allowed the installation to continue without interruptions. (The installation may have been progressing anyway, but it certainly was going slowly.)

[aaronfranke (arnfranke)]

I can confirm this bug. I tried to install without the format option because the install fails with the format option but apparently it also fails without the format option... this needs to be fixed.