I am experiencing the same behavior. It launches fine after a --reset, but not after exiting and relaunching.
It doesn't appear to matter if I'm opted into beta or not.
Running Steam on arch rolling 64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(1409240101_client)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steamwebhelper)/version(20140828032355)
Installing breakpad exception handler for appid(steamwebhelper)/version(1409196235)
Installing breakpad exception handler for appid(steamwebhelper)/version(20140828032355)
Installing breakpad exception handler for appid(steamwebhelper)/version(1409196235)
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
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
PulseAudio connect failed (used only for Mic Volume Control) with error: Access denied
Installing breakpad exception handler for appid(steam)/version(1409240101)
Uploading dump (out-of-process) [proxy '']
/tmp/dumps/assert_20140831153103_1.dmp
/home/tangent128/Steam/steam.sh: line 730: 27777 Segmentation fault (core dumped) $STEAM_DEBUGGER "$STEAMROOT/$STEAMEXEPATH" "$@"
Requested Force create but SharedObjectMutex already created
Forced create but already created for SharedObjectEvent
Forced create but already created for SharedObjectEvent
Finished uploading minidump (out-of-process): success = yes
response: CrashID=bp-a97e3f56-2e82-469b-9fc1-0d5372140831
Upon investigating it further: in my case the crash happens when you let steam remember the password.
Aha! Leaving "remember my password" unchecked seems to fix the problem for me too.
Nothing extracted yet.
Running Steam on Linux 2.6.34.14 32-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(1409240101_client)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steamwebhelper)/version(20140828032355)
Installing breakpad exception handler for appid(steamwebhelper)/version(1409196235)
Installing breakpad exception handler for appid(steamwebhelper)/version(20140828032355)
Installing breakpad exception handler for appid(steamwebhelper)/version(1409196235)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
PulseAudio connect failed (used only for Mic Volume Control) with error: Access denied
Installing breakpad exception handler for appid(steam)/version(1409240101)
Uploading dump (out-of-process) [proxy '']
/tmp/dumps/assert_20140830215526_1.dmp
/home/rambo/.local/share/Steam/steam.sh: line 730: 2044 Segmentation fault $STEAM_DEBUGGER "$STEAMROOT/$STEAMEXEPATH" "$@"
Requested Force create but SharedObjectMutex already created
Forced create but already created for SharedObjectEvent
Forced create but already created for SharedObjectEvent
Finished uploading minidump (out-of-process): success = yes
response: CrashID=bp-6af18ae9-6a21-48b2-918c-da67c2140830
When I remove ~/.local/share/Steam, steam will start OK (bootstrap will download the update and run without issues). I can even leave SteamApps and still be able to play the games, but steam crashes again on subsequent run.
All the previous releases worked like charm.