Steam worked fine on Ubuntu 13.10, but now crashes with segfault under optirun, however, without it works fine (obviously, with poor performance).

nazar-pc@nazar-pc:~$ optirun steam
Running Steam on ubuntu 14.04 64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
unlinked 0 orphaned pipes
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number
[0126/191909:WARNING:proxy_service.cc(958)] PAC support disabled because there is no system implementation
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
Installing breakpad exception handler for appid(steam)/version(1389129507_client)
Generating new string page texture 2: 48x256, total string texture memory is 49,15 KB
Generating new string page texture 3: 256x256, total string texture memory is 311,30 KB
Uploading dump (out-of-process) [proxy '']
/tmp/dumps/crash_20140126191908_1.dmp
/home/nazar-pc/.local/share/Steam/steam.sh: рядок 755: 6048 Помилка адресування (збережено знімок оперативної пам’яті) $STEAM_DEBUGGER "$STEAMROOT/$PLATFORM/$STEAMEXE" "$@"
Finished uploading minidump (out-of-process): success = no
error: Failure when receiving data from the peer

Dump: https://dl.dropboxusercontent.com/u/62195352/crash_20140126191908_1.dmp

System (without optirun):

Processor Information:
    Vendor:  GenuineIntel
    CPU Family:  0x6
    CPU Model:  0x3c
    CPU Stepping:  0x3
    CPU Type:  0x0
    Speed:  3800 Mhz
    8 logical processors
    4 physical processors
    HyperThreading:  Supported
    FCMOV:  Supported
    SSE2:  Supported
    SSE3:  Supported
    SSSE3:  Supported
    SSE4a:  Unsupported
    SSE41:  Supported
    SSE42:  Supported

Network Information:
    Network Speed:  

Operating System Version:
    Ubuntu Trusty Tahr (development branch) (64 bit)
    Kernel Name:  Linux
    Kernel Version:  3.13.0-haswell
    X Server Vendor:  The X.Org Foundation
    X Server Release:  11405000
    X Window Manager:  GNOME Shell
    Steam Runtime Version:  steam-runtime-release_2013-10-23

Video Card:
    Driver:  Intel Open Source Technology Center Mesa DRI Intel(R) Haswell Mobile x86/MMX/SSE2

    Driver Version:  3.0 Mesa 10.1.0-devel
    OpenGL Version: 3.0
    Desktop Color Depth: 24 bits per pixel
    Monitor Refresh Rate: 30 Hz
    VendorID:  0x10de
    DeviceID:  0x119f
    Number of Monitors:  2
    Number of Logical Video Cards:  2
    Primary Display Resolution:  3840 x 2160
    Desktop Resolution: 5760 x 2160
    Primary Display Size: 33,62" x 18,94"  (38,58" diag)
                                            85,4cm x 48,1cm  (98,0cm diag)
    Primary VRAM Not Detected

Sound card:
    Audio device: Intel Haswell HDMI

Memory:
    RAM:  7904 Mb

Miscellaneous:
    UI Language:  English
    LANG:  uk_UA.UTF-8
    Microphone:  Not set
    Total Hard Disk Space Available:  51321 Mb
    Largest Free Hard Disk Block:  25451 Mb

Installed software:

Recent Failure Reports:
    Sun Jan 26 17:10:36 2014 GMT: file ''/tmp/dumps/crash_20140126191027_1.dmp'', upload yes: ''CrashID=bp-761a9223-4c0a-4466-9cb3-e567b2140126''
    Sun Jan 26 17:19:17 2014 GMT: file ''/tmp/dumps/crash_20140126191908_1.dmp'', upload no: ''Failure when receiving data from the peer'' 

Discrete video card is Nvidia GeForce 780M, CPU Intel Core i7-4900MQ

I'll be happy to provide any additional information to fix this issue ASAP.