CodeMiller

Fixing flashing Fedora: Linux boot issue solution

I installed a bunch of development tools and packages today on a Linux laptop running Fedora 18 and when I restarted the machine I was only able to boot into single-user mode.

It’s not the first time that has happened to me, but the fix for this particular issue came from asking one of my kernel hacker colleagues for a bit of direction, so I thought I should document it for anyone else who might get stuck.

Symptoms:

When the machine booted, it got to a point and then the display started flashing on and off. It would show the start-up logging, then go to black, then about two seconds later come back again — and repeat. The log output was no longer progressing.

Analysis:

I booted into single-user mode and had a look at the logs. I found that /var/log/messages included repeated blocks of output like this:

localhost systemd[1]: lightdm.service: main process exited, code=exited, status=1/FAILURE
localhost systemd[1]: Unit lightdm.service entered failed state
localhost systemd[1]: lightdm.service holdoff time over, scheduling restart.
localhost systemd[1]: Stopping Light Display Manager...
localhost systemd[1]: Starting Light Display Manager...
localhost systemd[1]: Started Light Display Manager.


This was as much detail as was provided, so I went to /var/log/lightdm to have a look at the LightDM logs.

The lightdm.log file pointed me to a failure with Greeter, but didn’t give any further details. The relevant Greeter log file finally gave me the error I was hunting for:

lightdm-gtk-greeter symbol lookup error /lib/libGL.so.1 undefined symbol _glapi_tls_Dispatch

A Google search gave me no results for this error. Before I attempted to delve any deeper myself, I asked a kernel hacker colleague, and he knew off the top of his head the packages involved and what the problem was likely to be. He advised me to check that all my Mesa packages were the same version:

rpm -qa | grep mesa

I’m not sure how or why they got that way, but the mesa-* packages were indeed from two different versions.

Solution:

I updated all the Mesa packages so the versions aligned (I had to start NetworkManager first as by default there is no network access in single-user mode):

yum update mesa* -y

Problem solved. I hope this helps someone else who perhaps isn’t fortunate enough to work alongside someone like my knowledgeable colleague.

The Journalist Who Became a Software Engineer

May I present a play that is performed frequently in the story of my life.

Narrator: Person X knew Katie was a software engineer but they have just discovered that she used to work as…(with shock) a journalist.

Person X (surprised): How on earth did you go from journalism to IT?

Katie (pauses, to decide which variation of the answer to go with this time): Well…

(EDIT: Script changed to reflect recent developments.)

Narrator: InformIT offered Katie the chance to tell her story in an article on its site, which has just been published.

Katie (with relief): …you can read all about it at InformIT.com.

End of Story

The information technology industry offers a broad range of job opportunities, but if you’ve started your career in another arena, how do you go about making the switch? In this article, former journalist Katie Miller shares her experience of transitioning into the tech world and offers advice for others aspiring to follow suit.