我似乎无法在Arch Linux上构建虚幻引擎v4：
ryanvade@ryanvade-arch:/build/UnrealEngine$ ./Setup.sh
Registering git hooks... (this will override existing ones!)
Github build
Checking / downloading the latest archives
Checking dependencies (excluding Win32, Win64, Mac, HTML5, Android)...
The following file(s) have been modified:
Engine/Binaries/DotNET/AutomationScripts/AutomationScripts.Automation.dll
Engine/Binaries/DotNET/AutomationTool.exe
Engine/Binaries/DotNET/DotNETUtilities.dll
Engine/Binaries/DotNET/UnrealBuildTool.exe
Would you like to overwrite your changes (y/n)? y
Received 4/4 files (0.9/0.9mb; 0.14mb/s; 100%)...
Fixing inconsistent case in filenames.
Building ThirdParty libraries
If you don't see SUCCESS message in the end, then building did not finish properly.
In that case, take a look into /build/UnrealEngine/Engine/Build/BatchFiles/Linux/BuildThirdParty.log for details.
==> BuildLND
********** SUCCESS ****************
ryanvade@ryanvade-arch:/build/UnrealEngine$ ./GenerateProjectFiles.sh
Setting up Unreal Engine 4 project files...
+ xbuild Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj /verbosity:quiet /nologo /p:TargetFrameworkVersion=v4.0 /p:Configuration=Development
+ xbuild Source/Programs/AutomationTool/AutomationTool_Mono.csproj /verbosity:quiet /nologo /p:TargetFrameworkVersion=v4.0 /p:Platform=AnyCPU /p:Configuration=Development
+ xbuild Source/Programs/AutomationTool/Scripts/AutomationScripts.Automation.csproj /verbosity:quiet /nologo /p:TargetFrameworkVersion=v4.0 /p:Configuration=Development
+ xbuild Source/Programs/AutomationTool/Linux/Linux.Automation.csproj /verbosity:quiet /nologo /p:TargetFrameworkVersion=v4.0 /p:Configuration=Development
/build/UnrealEngine/Engine/Source/Programs/AutomationTool/Linux/Linux.Automation.csproj: warning : Project has unknown ToolsVersion '11.0'. Using the default tools version '2.0' instead.
/usr/lib/mono/2.0/Microsoft.Common.targets: warning : TargetFrameworkVersion 'v4.0' not supported by this toolset (ToolsVersion: 2.0).
LinuxPlatform.Automation.cs(246,25): error CS0117: `System.IO.Directory' does not contain a definition for `EnumerateFiles'
LinuxPlatform.Automation.cs(17,91): error CS0117: `System.Environment.SpecialFolder' does not contain a definition for `UserProfile'
我安装了Mono：
ryanvade@ryanvade-arch:/build/UnrealEngine$ mono --version
Mono JIT compiler version 3.12.0 (tarball Thu Jan 15 18:46:56 UTC 2015)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
TLS: __thread
SIGSEGV: altstack
Notifications: epoll
Architecture: amd64
Disabled: none
Misc: softdebug
LLVM: supported, not enabled.
GC: sgen
我错过了什么吗？