Running Arch Linux on a laptop with NVIDIA Optimus.
$ primusrun glxinfo | grep 'OpenGL version'
OpenGL version string: 4.5.0 NVIDIA 352.21
$ LD_PRELOAD=/usr/lib/nvidia/libGL.so PRIMUS_SYNC=1 primusrun ./UE4Editor-Linux-Debug -nosplash
[2015.06.20-00.08.43:524][ 0]Log file open, 06/20/15 01:08:43
[2015.06.20-00.08.43:524][ 0]LogInit:Display: Running engine without a game
[2015.06.20-00.08.43:524][ 0]LogInit:Display: RandInit(-1968654583) SRandInit(-1968654574).
[2015.06.20-00.08.43:524][ 0]LogTaskGraph: Started task graph with 4 named threads and 7 total threads.
[2015.06.20-00.08.43:525][ 0]LogStats: Stats thread started
[2015.06.20-00.08.43:525][ 0]LogInit: Version: 4.8.1-0+++depot+UE4-Releases+4.8
[2015.06.20-00.08.43:525][ 0]LogInit: API Version: 0
[2015.06.20-00.08.43:525][ 0]LogInit: Compiled (64-bit): Jun 20 2015 00:54:49
[2015.06.20-00.08.43:525][ 0]LogInit: Compiled with Clang: 3.6.1 (tags/RELEASE_361/final)
[2015.06.20-00.08.43:525][ 0]LogInit: Build Configuration: Debug
[2015.06.20-00.08.43:525][ 0]LogInit: Branch Name: ++depot+UE4-Releases+4.8
[2015.06.20-00.08.43:525][ 0]LogInit: Command line: -nosplash
[2015.06.20-00.08.43:525][ 0]LogInit: Base directory: /home/felix/devel/UnrealEngine/Engine/Binaries/Linux/
[2015.06.20-00.08.43:525][ 0]LogInit: Rocket: 0
[2015.06.20-00.08.43:599][ 0]LogInit: Using libcurl 7.38.0
[2015.06.20-00.08.43:599][ 0]LogInit: - built for x86_64-unknown-linux-gnu
[2015.06.20-00.08.43:599][ 0]LogInit: - supports SSL with OpenSSL/1.0.1i
[2015.06.20-00.08.43:599][ 0]LogInit: - supports HTTP deflate (compression) using libz 1.2.5
[2015.06.20-00.08.43:599][ 0]LogInit: - other features:
[2015.06.20-00.08.43:599][ 0]LogInit: CURL_VERSION_SSL
[2015.06.20-00.08.43:599][ 0]LogInit: CURL_VERSION_LIBZ
[2015.06.20-00.08.43:599][ 0]LogInit: CURL_VERSION_IPV6
[2015.06.20-00.08.43:599][ 0]LogInit: CURL_VERSION_ASYNCHDNS
[2015.06.20-00.08.43:599][ 0]LogInit: CURL_VERSION_LARGEFILE
[2015.06.20-00.08.43:600][ 0]LogInit: CURL_VERSION_TLSAUTH_SRP
[2015.06.20-00.08.43:600][ 0]LogInit: Libcurl: checking if '/etc/pki/tls/certs/ca-bundle.crt' exists
[2015.06.20-00.08.43:600][ 0]LogInit: Libcurl: checking if '/etc/ssl/certs/ca-certificates.crt' exists
[2015.06.20-00.08.43:602][ 0]LogInit: CurlRequestOptions (configurable via config and command line):
[2015.06.20-00.08.43:602][ 0]LogInit: - bVerifyPeer = true - Libcurl will verify peer certificate
[2015.06.20-00.08.43:603][ 0]LogInit: - bUseHttpProxy = false - Libcurl will NOT use HTTP proxy
[2015.06.20-00.08.43:603][ 0]LogInit: - bDontReuseConnections = false - Libcurl will reuse connections
[2015.06.20-00.08.43:603][ 0]LogInit: - CertBundlePath = /etc/ssl/certs/ca-certificates.crt - Libcurl will set CURLOPT_CAINFO to it
[2015.06.20-00.08.43:630][ 0]LogOnline:Warning: No default platform service specified for OnlineSubsystem
[2015.06.20-00.08.43:763][ 0]LogInit: Presizing for 0 objects not considered by GC, pre-allocating 0 bytes.
[2015.06.20-00.08.44:119][ 0]LogInit: Object subsystem initialized
[2015.06.20-00.08.44:192][ 0]LogInit: Initializing SDL.
[2015.06.20-00.08.45:242][ 0]LogInit: Display metrics:
[2015.06.20-00.08.45:242][ 0]LogInit: PrimaryDisplayWidth: 1920
[2015.06.20-00.08.45:242][ 0]LogInit: PrimaryDisplayHeight: 1080
[2015.06.20-00.08.45:242][ 0]LogInit: PrimaryDisplayWorkAreaRect:
[2015.06.20-00.08.45:242][ 0]LogInit: Left=0, Top=0, Right=1920, Bottom=1080
[2015.06.20-00.08.45:242][ 0]LogInit: VirtualDisplayRect:
[2015.06.20-00.08.45:242][ 0]LogInit: Left=0, Top=0, Right=1920, Bottom=1080
[2015.06.20-00.08.45:242][ 0]LogInit: TitleSafePaddingSize: X=0.000 Y=0.000
[2015.06.20-00.08.45:242][ 0]LogInit: ActionSafePaddingSize: X=0.000 Y=0.000
[2015.06.20-00.08.45:242][ 0]LogInit: Number of monitors: 1
[2015.06.20-00.08.45:242][ 0]LogInit: Monitor 0
[2015.06.20-00.08.45:242][ 0]LogInit: Name: 0
[2015.06.20-00.08.45:242][ 0]LogInit: ID: display0
[2015.06.20-00.08.45:242][ 0]LogInit: NativeWidth: 1920
[2015.06.20-00.08.45:242][ 0]LogInit: NativeHeight: 1080
[2015.06.20-00.08.45:242][ 0]LogInit: bIsPrimary: true
[2015.06.20-00.08.45:277][ 0]LogInit: Selected Device Profile: [Linux]
[2015.06.20-00.08.45:277][ 0]LogInit: Applying CVar settings loaded from the selected device profile: [Linux]
[2015.06.20-00.08.45:339][ 0]LogInit: Linux hardware info:
[2015.06.20-00.08.45:339][ 0]LogInit: - this process' id (pid) is 18948, parent process' id (ppid) is 19718
[2015.06.20-00.08.45:339][ 0]LogInit: - we are not running under debugger
[2015.06.20-00.08.45:339][ 0]LogInit: - machine network name is 'leikeze'
[2015.06.20-00.08.45:339][ 0]LogInit: - we're logged in locally
[2015.06.20-00.08.45:339][ 0]LogInit: - Number of physical cores available for the process: 4
[2015.06.20-00.08.45:339][ 0]LogInit: - Number of logical cores available for the process: 8
[2015.06.20-00.08.45:339][ 0]LogInit: - Memory allocator used: binned
[2015.06.20-00.08.45:339][ 0]LogInit: Linux-specific commandline switches:
[2015.06.20-00.08.45:339][ 0]LogInit: -nodwarf (currently OFF): suppress parsing of DWARF debug info (callstacks will be generated faster, but won't have line numbers)
[2015.06.20-00.08.45:339][ 0]LogInit: -ansimalloc - use malloc()/free() from libc (useful for tools like valgrind and electric fence)
[2015.06.20-00.08.45:339][ 0]LogInit: -jemalloc - use jemalloc for all memory allocation
[2015.06.20-00.08.45:339][ 0]LogInit: -binnedmalloc - use binned malloc for all memory allocation
[2015.06.20-00.08.45:339][ 0]LogInit: -httpproxy=ADDRESS:PORT - redirects HTTP requests to a proxy (only supported if compiled with libcurl)
[2015.06.20-00.08.45:339][ 0]LogInit: -reuseconn - allow libcurl to reuse HTTP connections (only matters if compiled with libcurl)
[2015.06.20-00.08.45:339][ 0]LogInit: -virtmemkb=NUMBER - sets process virtual memory (address space) limit (overrides VirtualMemoryLimitInKB value from .ini)
[2015.06.20-00.08.45:339][ 0]LogInit: Setting LC_NUMERIC to en_US
[2015.06.20-00.08.45:339][ 0]LogInit: - Physical RAM available (not considering process quota): 8 GB (7882 MB, 8071200 KB, 8264908800 bytes)
[2015.06.20-00.08.45:578][ 0]LogTextLocalizationManager: The requested culture ('en_GB') has no localization data; parent culture's ('en') localization data will be used.
[2015.06.20-00.08.46:039][ 0]LogTextLocalizationManager:Warning: Loaded localization resources contain conflicting entries for (Namespace:ContentBrowser, Key:ImportAssetToolTip):
Localization Resource: (/home/felix/devel/UnrealEngine/Engine/Content/Localization/Editor/en/Editor.locres) Source String Hash: (-630476809) Localized String: (Import to {0}...)
Localization Resource: (/home/felix/devel/UnrealEngine/Engine/Content/Localization/Editor/en/Editor.locres) Source String Hash: (1271782899) Localized String: (Imports an asset from file to this folder.)
[2015.06.20-00.08.46:766][ 0]LogLinux:Error: appError called: Assertion failed: Assertion failed: [File:/home/felix/devel/UnrealEngine/Engine/Source/Runtime/OpenGLDrv/Private/Linux/OpenGLLinux.cpp] [Line: 183]
_PlatformCreateOpenGLContextCore - Could not create OpenGL 3.2 context, SDL error: 'Could not create GL context: GLXBadFBConfig'
[2015.06.20-00.08.47:049][ 0]LogLinux: === Critical error: ===
Unhandled Exception: SIGSEGV: invalid attempt to access memory at address 0x00000003
[2015.06.20-00.08.47:050][ 0]LogLinux: Assertion failed: Assertion failed: [File:/home/felix/devel/UnrealEngine/Engine/Source/Runtime/OpenGLDrv/Private/Linux/OpenGLLinux.cpp] [Line: 183]
_PlatformCreateOpenGLContextCore - Could not create OpenGL 3.2 context, SDL error: 'Could not create GL context: GLXBadFBConfig'
[Callstack] 02 0x00007f26102fe368 ReportCrash(FLinuxCrashContext const&)
[Callstack] 03 0x00000000004acbfb EngineCrashHandler(FGenericCrashContext const&) [/home/felix/devel/UnrealEngine/Engine/Intermediate/Build/Linux/x86_64-unknown-linux-gnu/UE4Editor/Debug/Launch/Module.Launch.cpp, line 0]
[Callstack] 04 0x00007f2610307b98 PlatformCrashHandler(int, siginfo_t*, void*)
[Callstack] 05 0x00007f25ff98d5b0 /usr/lib/libc.so.6(+0x335b0) [0x7f25ff98d5b0]
[Callstack] 06 0x00007f261031abd9 FOutputDeviceLinuxError::Serialize(wchar_t const*, ELogVerbosity::Type, FName const&)
[Callstack] 07 0x00007f2610566edc FOutputDevice::Logf(wchar_t const*, ...)
[Callstack] 08 0x00007f26104fdccb FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, ...)
[Callstack] 09 0x00007f25e0c126aa /home/felix/devel/UnrealEngine/Engine/Binaries/Linux/libUE4Editor-OpenGLDrv-Linux-Debug.so(+0x1886aa) [0x7f25e0c126aa]
[Callstack] 10 0x00007f25e0b5749d PlatformInitOpenGL()
[Callstack] 11 0x00007f25e0b7be81 FOpenGLDynamicRHIModule::IsSupported()
[Callstack] 12 0x00007f26075a0a9f PlatformCreateDynamicRHI()
[Callstack] 13 0x00007f26075a05bd RHIInit(bool)
[Callstack] 14 0x000000000042d907 FEngineLoop::PreInit(wchar_t const*) [/home/felix/devel/UnrealEngine/Engine/Intermediate/Build/Linux/x86_64-unknown-linux-gnu/UE4Editor/Debug/Launch/Module.Launch.cpp, line 0]
[Callstack] 15 0x000000000041f182 EnginePreInit(wchar_t const*) [/home/felix/devel/UnrealEngine/Engine/Intermediate/Build/Linux/x86_64-unknown-linux-gnu/UE4Editor/Debug/Launch/Module.Launch.cpp, line 0]
[Callstack] 16 0x0000000000484b97 GuardedMain(wchar_t const*) [/home/felix/devel/UnrealEngine/Engine/Intermediate/Build/Linux/x86_64-unknown-linux-gnu/UE4Editor/Debug/Launch/Module.Launch.cpp, line 0]
[Callstack] 17 0x00000000004af575 ./UE4Editor-Linux-Debug(main+0x28e5) [0x4af575] [/home/felix/devel/UnrealEngine/Engine/Intermediate/Build/Linux/x86_64-unknown-linux-gnu/UE4Editor/Debug/Launch/Module.Launch.cpp, line 0]
[Callstack] 18 0x00007f25ff97a790 /usr/lib/libc.so.6(__libc_start_main+0xf0) [0x7f25ff97a790]
[Callstack] 19 0x000000000041ee99 ./UE4Editor-Linux-Debug(_start+0x29) [0x41ee99]