Dowload the latest jockey-common here (look for date modified):
http://security.ubuntu.com/ubuntu/pool/main/j/jockey/

Install it

I have manually installed jockey-common_0.9.7-0ubuntu7.15_all.deb and python-xkit_0.5.0ubuntu2_all.deb (from here, as the Ubuntu package depends on it and it is not available in Debian jessie), but to no avail. I still get the very same problem.

I'd definitely prefer to stay on jessie, especially since I can't change it back once I upgraded. I originally intended to run the current stable, but that doesn't work too well with the AMD Catalyst 14.4. Right now, fglrx-driver is the same version in jessie as it is in sid.

As mentioned in the first post, I was indeed able to log in and use Steam while using the open source drivers; however, after switching to the proprietary ones, that stopped. I explicitly followed the "install open source drivers, install and update steam, log in, install proprietary drivers" instructions, but that sadly yielded no results.

Until now I've only tried it with the steam package from the repositories, which didn't even tell me of any segfault, but just quit; so I did it differently this time:

As instructed I completely removed the proprietary drivers as well as all remainings of Steam, rebooted, then installed Steam from the .deb via gdebi. I was able to launch it just fine, logged in and configured it a bit. I decided to do a reboot just to be sure, then proceeded to reinstall the proprietary drivers. After that was done and I finished rebooting, I got the segfault warning when trying to start Steam.

Here is my slightly annotated .bash_history, so you can see whether I did something wrong.
And here is the exact error I'm getting now, using the steam installed via the provided .deb file; it appears to be a pretty common error.

I can see the problem after looking at your .bash_history. Removing .steam does nothing. You still have the older Steam bootstrapper from the repos. If you look at the folder under .steam, they are all symlinks to .local/share/Steam. Repeat what you did before and rm -rf .local/share/Steam first.

It looks like you are just copying over an older xorg.conf. I don't know if that works for you, but it might be safer to just run aticonfig --initial after installing fglrx-driver.

Thank you. I have done as you said and indeed, I still had a .local/share/steam folder, so I deleted that in addition with the other folders. This time, I let aticonfig --initial handle the creation of the xorg.conf file again and manually adjusted it using the AMD CCC after, but that really shouldn't make a difference as the xorg.conf file I have been copying was from two days ago.

Anyway, it's the same story again. Worked with open-source drivers, segfaulted with the proprietary drivers, even after completely removing .local/share/steam. That said, the manually installed .deb you linked me to, which I used to install Steam, recreated .local/share/steam and indeed, most of my files are there. If this is not intentional behaviour (perhaps Debian-specific?), then that might be what's wrong here, I'm just absolutely not sure what's causing it.

BitVortex, Not sure if this will help you or not, but did you update to the Steam Beta client before installing fglrx? You can update to Steam Beta by going to Steam -> Settings -> Account -> Beta Participation and opt-in to Steam Beta client.

installing libxinerama1:i386 (with fglrx) steam install and run without problems.

Ubuntu 14.04 lts 64bit

Okay, I've tried both of that now. Did the usual routine of purging everything belonging to the proprietary drivers as well as removing and remaining files of Steam (even did a sudo find . -name "*steam*" from /, but found no other files); then rebooted, installed and updated Steam.

Again, I was able to log in just fine, this time I even switched to the beta client and can confirm that I can launch that just fine with open-source drivers, too. When installing the proprietary driver again, I added libxinerama1:i386 to the install queue (libxinerama1:amd64 was still installed). Like usual, I was unable to launch Steam after the reboot, same problem as reported before. I even tried enabling Xinerama in the AMD CCC and rebooted, but that also didn't change anything.

I know that this is kind of a duplicate, but apparently none of the previously found fixes/workarounds appears to be working for my case. I'm not sure why that is, maybe it's due to me having a relatively new graphics card that is meagerly supported by the open-source drivers, or because of the multi-monitor setup.

You should try another Linux distribution if you really need Steam on Linux and Debian isn't working for you. It should work on Ubuntu 14.04 just fine.

I tried reporting this problem with Steam and the fglrx driver segfaulting several months ago and I was told it was an issue with the AMD drivers and to report it to them. This workaround is the only way I know to get Steam and fglrx working.

Thank you all for your help.
As of right now, it appears like I just can't get it working on my system. While that's less-than-ideal, it isn't too bad for now, as I can still use the community features via browser and access my games with a Win7-dualboot. I hope this issue gets resolved until jessie gets frozen at the end of this year, whether Steam itself, the AMD drivers, the Kernel or anything else is at fault here; if I manage to get it working earlier than that, I'll report back.

Updated to kernel 3.14-1 a few hours ago; the problem persists with this setup, a complete removal & reinstall as described above did not work.

I decided to try the Steam-Installer for Debian Wheezy, despite using jessie, in hope that the shipped libraries would be of any help. But again, after updating Steam and logging in, a reboot preceded by the installation of the AMD Catalyst drivers made me stare at the terminal again, telling me of a segmentation fault in the very same line.

According to [issue #3186](https://github.com/ValveSoftware/steam-for-linux/issues/3186) this should have been fixed with the driver that I currently am using (and which I have used since the beginning of this report), which obviously is not the case for me.

I have no issues running Steam on Debian Sid with fglrx-driver. Ask me anything.

Thank you. I'm no expert at debugging, but let's try.

Could you provide me with the full output of uname -a, your current /etc/X11/xorg.conf (which is probably auto-generated), and the output of apt-cache policy steam, apt-cache policy steam-launcher and apt-cache policy fglrx-driver?

Fglrx most likely will also need to be patched to support the 3.14 kernel, Fedora 20 users have also reported issues and a guide has been posted at http://bluehatrecord.wordpress.com/2014/05/10/installing-the-proprietary-amd-catalyst-14-4-fglrx-driver-on-fedora-20-with-kernel-3-14/. (Some mental translation required for Debian.)

Sorry for the late response. Here is the info you requested.

uname -a

/etc/X11/xorg.conf
apt-cache policy steam
apt-cache policy steam-launcher
apt-cache policy fglrx-driver

Here is my hardware info in case you are curious. I use a tool called inxi in the repos.
inxi -Fxz

I hope this helps.

OK, your uname -a output matches mine, so a different kernel version isn't the problem.

Your xorg.conf is considerably short compared to my xorg.conf, but apart from the fact that I have 3 monitors connected, I don't see a major difference here; at least none that could trigger a segmentation fault in an application.

We use exactly the same fglrx-driver version. Your steam-launcher version equals the one of my steam-debian, but I guess I'll try installing it from the Steam repositories again.

Thanks for additionally linking your output fo inxi -Fxz; it is remarkably similar to what I've got. Apart from the multiple monitors and slightly higher CPC version (whatever that means), all other software in the graphics card section is exactly the same.

I'm glad you're trying to help me; I'll reinstall Steam from the official Steam repositories now and report back when that's done and while doing that, I'll try to think of other information that could be of any use. What I've gathered from this is that it should work, but doesn't.

EDIT: Again, steam-launcher from the Steam repositories worked with the free drivers, but not with the AMD Catalyst. Same kernel, same driver, same Steam binary, only minor differences in the setup. Any ideas left? How about the full output of apt-cache policy fglrx-atieventsd fglrx-control fglrx-driver fglrx-modules-dkms libfglrx glx-alternative-fglrx libgl1-fglrx-glx libgl1-fglrx-glx:i386 libgl1-fglrx-glx-i386 libfglrx libfglrx-amdxvba1 xvba-va-driver, so I can see what AMD-related packages you have installed?

I used to have your same motherboard before I sold it and upgraded to a 970 chipset. I upgraded it because yours doesn't support newer FX (AM3+) processors, and for the UEFI BIOS. Otherwise it was a very stable motherboard.

Here is the info you wanted:

fglrx

And once more my system feels like a copy of yours; apart from having xvba-va-driver installed, my packages and package versions don't differ one bit from yours. I guess in the end all I can hope for is a driver update from AMD in which they fix this, which might or might not take ages.

Any more ideas are welcome, but I begin to feel like this is out of my control.

I hate to reiterate this, but have you tried another distribution like Ubuntu to install Steam? Ubuntu is based on Debian, but at least you can see if it works with Steam.

No, but I guess I'll try it with a persistent installation of the newest Ubuntu to an USB-Stick in the next few days.

Ubuntu works fine with steam and fglrx