I also get a segfault when running steam with STEAM_RUNTIME disabled now.
Here's my command line output: https://gist.github.com/uberscientist/0fb08a8f4e26de094ec5
With STEAM_RUNTIME libs it runs fine (however TF2 fails to start...)
If I can provide any more useful information let me know. I am running Arch Linux, systemd (so OpenRC probably has nothing to do with it), x86_64.

same thing here on ArchLinux. I've been removing libraries from steam_runtime one after the other to find out which ones can't be removed and can't be replaced by the ones provided by the host system.

I've been able to narrow it down to libnm. I'll test it later, but I suspect an update on libnm-glib to 0.9.10 to be incompatible with Steam (expecting 0.9.8). That would be the second time I have problem with libnm in the last year. I don't see why a minor update (from 0.9.8 to 0.9.10) would break Steam, there must be something wrong on how it is being used or on how libnm is being developped.

Same issue here as well when trying to use the native runtime of Archlinux:

phaazon@illusion ~ % STEAM_RUNTIME=0 steam
/home/phaazon/.local/share/Steam/steam.sh: line 161: VERSION_ID: unbound variable
/home/phaazon/.local/share/Steam/steam.sh: line 161: VERSION_ID: unbound variable
Running Steam on arch  64-bit
STEAM_RUNTIME is disabled by the user
Installing breakpad exception handler for appid(steam)/version(1424305157)
Installing breakpad exception handler for appid(steam)/version(1424305157)

(steam:14838): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steam:14838): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steam:14838): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steam:14838): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steam:14838): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steam:14838): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steam:14838): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",
Installing breakpad exception handler for appid(steam)/version(1424305157)

(steamwebhelper:14841): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steamwebhelper:14841): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steamwebhelper:14841): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steamwebhelper:14841): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steamwebhelper:14841): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steamwebhelper:14841): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",

(steamwebhelper:14841): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",
Installing breakpad exception handler for appid(steamwebhelper)/version(20150218153139)
Installing breakpad exception handler for appid(steamwebhelper)/version(1424273499)
Installing breakpad exception handler for appid(steamwebhelper)/version(20150218153139)
Installing breakpad exception handler for appid(steamwebhelper)/version(1424305157)
Installing breakpad exception handler for appid(steamwebhelper)/version(1424305157)
/home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/vgui2/src/../vgui_surfacelib/FontManager.cpp (276) : Assertion Failed: descs.Count() >= 1
Assert( Assertion Failed: descs.Count() >= 1 ):/home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/vgui2/src/../vgui_surfacelib/FontManager.cpp:276

Installing breakpad exception handler for appid(steam)/version(1424305157)
crash_20150324002021_5.dmp[14864]: Uploading dump (out-of-process)
/tmp/dumps/crash_20150324002021_5.dmp
/home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/vgui2/src/../vgui_surfacelib/FontManager.cpp (276) : Assertion Failed: descs.Count() >= 1
/home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/vgui2/src/../vgui_surfacelib/FontManager.cpp (276) : Assertion Failed: descs.Count() >= 1
/home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/vgui2/src/../vgui_surfacelib/FontManager.cpp (276) : Assertion Failed: descs.Count() >= 1
Installing breakpad exception handler for appid(steam)/version(1424305157)
Installing breakpad exception handler for appid(steam)/version(1424305157)
Installing breakpad exception handler for appid(steam)/version(1424305157)
Installing breakpad exception handler for appid(steam)/version(1424305157)
Installing breakpad exception handler for appid(steam)/version(1424305157)
Installing breakpad exception handler for appid(steam)/version(1424305157)
FillInMachineIDInfo took a total of 0 milliseconds
Installing breakpad exception handler for appid(steam)/version(1424305157)
Installing breakpad exception handler for appid(steam)/version(1424305157)

(steam:14838): GLib-GObject-WARNING **: invalid unclassed pointer in cast to 'NMRemoteSettings'

(steam:14838): GLib-GObject-CRITICAL **: g_type_instance_get_private: assertion 'instance != NULL && instance->g_class != NULL' failed

(steam:14838): GLib-GObject-CRITICAL **: g_type_instance_get_private: assertion 'instance != NULL && instance->g_class != NULL' failed
assert_20150324002020_1.dmp[14879]: Uploading dump (out-of-process)
/tmp/dumps/assert_20150324002020_1.dmp
/home/phaazon/.local/share/Steam/steam.sh: line 757: 14838 Segmentation fault      (core dumped) $STEAM_DEBUGGER "$STEAMROOT/$STEAMEXEPATH" "$@"

phaazon, if you are on Arch, add the alucryd-multilib repository and install lib32-libnm-glib46. This may fix your NMRemoteSettings error. You may need to install some other libs also. See https://wiki.archlinux.org/index.php/unofficial_user_repositories#alucryd-multilib for the repository.

Thank you, I’ll test that tonight.

@sergioad , @phaazon , @uberscientist : did using the alucryd-multilib repository and installing the lib32-libnm-glib (...-glib46) fixed the problem for you, since you are all on Arch? I'm trying to help somebody using OpenSUSE Tumbleweed and I suspect he is hitting the same issue as this one: the shipped libnm is 1.0.0, which has an incompatible API with the 0.9.8 version used by Steam.

@Oxalin nope. Still the same issue.

@Oxalin Same issue as well, I also have to set a correct LD_LIBRARY_PATH before executing now too: STEAM_RUNTIME=0 LD_LIBRARY_PATH="/usr/lib32" steam

and it's still seg faulting... probably not a high priority to fix it.

@Oxalin I used it on a 32 bits system

@uberscientist , the LD_LIBRARY_PATH is not set by default. You could add it as empty at boot. There is a specific bug about it. Steam launch script would only need a really simple modification to be fixed, but seems to be a really low priority sadly.

We can work on your problem from there. I can't remember exactly all I did to make it work properly, but I think I have some mother libs frtom the alucryd repository. But I could try to find the deleted libs from Steam and all the needed libs from alucryd. I'll have a look at home.

Same issue. Was hoping to figure out why AoW3 slows down when running in steam environment, but I guess tough luck, huh.
Archlinux, x86_64, all the deps installed (even lib32-p11-kit fixed manually).

To all of the ones using Archlinux (and maybe Manjaro), about alucryd repository, could you install the steam-libs package? That will let you know if you have any other libraries that should be pulled from alucryd or missing ones (just in case).

@Oxalin Seems alucryd is missing one package but dont think its related.

Libteam is missing for x86_64, arch repo got 1.14-2 while alucryd is using 1.11 but not supplying a x86_64 package for it and it fails for me to install.

Other than that, FontManager.cpp (276) errors, font issue maybe?

@CommanderAlchemy , yes, I see. However, Archlinux provides the 1.14-2 version both for 32 and 64bit. They are the one installed on my system, and I don't have any problem with them. Maybe Alucryd should remove or modify the steam-libs dependencies, but that is another story.

About the FontManager.cpp errors, I don't think you need to worry about them. I have the same errors and everything works fine.