安装 YouCompleteMe 的 OmniSharpServer 出现了一个错误

[bwangel]

换了一个系统， xubuntu14 ，然后今天安装 YCM 的时候出错了错误，我的安装指令是./install.py -all

msbuild or xbuild is required to build Omnisharp

后来查到了这篇回答，why-is-omnisharp-not-working，看到了 programingfrik 的答案，说是omnisharp没能正确安装，于是我切换到YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer目录下，执行了一下安装指令

git checkout master
git submodule update --init --recursive
sudo apt-get install mono-xbuild
xbuild

然后又报错了，这回不知道该咋办了，特来向 V 友们求助！

我的分支和 mono 版本是这样的：

➜ /home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer (master) $ git branch -v
* master e190291 Merge pull request #207 from micbou/drive-letter
➜ /home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer (master) $ mono --version
Mono JIT compiler version 3.2.8 (Debian 3.2.8+dfsg-4ubuntu1.1)
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

报的错误是这样的：

➜ /home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer (master) $ xbuild
XBuild Engine Version 12.0
Mono, Version 3.2.8.0
Copyright (C) 2005-2013 Various Mono authors

Build started 4/22/2016 10:44:14 PM.
__________________________________________________
Project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp.sln" (default target(s)):
	Target ValidateSolutionConfiguration:
		Building solution configuration "Debug|Any CPU".
	Target Build:
		Project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/Microsoft.Build.Evaluation/Microsoft.Build.Evaluation.csproj" (default target(s)):
			Target PrepareForBuild:
: error : Error initializing task Message: Could not load file or assembly 'Microsoft.Build.Tasks.v4.0' or one of its dependencies. The system cannot find the file specified.
			Task "Message" execution -- FAILED
			Done building target "PrepareForBuild" in project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/Microsoft.Build.Evaluation/Microsoft.Build.Evaluation.csproj".-- FAILED
			Target _RecordCleanFile:
: error : Error initializing task ReadLinesFromFile: Could not load file or assembly 'Microsoft.Build.Tasks.v4.0' or one of its dependencies. The system cannot find the file specified.
			Task "ReadLinesFromFile" execution -- FAILED
			Done building target "_RecordCleanFile" in project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/Microsoft.Build.Evaluation/Microsoft.Build.Evaluation.csproj".-- FAILED
		Done building project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/Microsoft.Build.Evaluation/Microsoft.Build.Evaluation.csproj".-- FAILED
		Project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/NRefactory/ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj" (default target(s)):
			Target PrepareForBuild:
: error : Error initializing task Message: Could not load file or assembly 'Microsoft.Build.Tasks.v4.0' or one of its dependencies. The system cannot find the file specified.
			Task "Message" execution -- FAILED
			Done building target "PrepareForBuild" in project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/NRefactory/ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj".-- FAILED
			Target _RecordCleanFile:
: error : Error initializing task ReadLinesFromFile: Could not load file or assembly 'Microsoft.Build.Tasks.v4.0' or one of its dependencies. The system cannot find the file specified.
			Task "ReadLinesFromFile" execution -- FAILED
			Done building target "_RecordCleanFile" in project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/NRefactory/ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj".-- FAILED
		Done building project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/NRefactory/ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj".-- FAILED
	Task "MSBuild" execution -- FAILED
	Done building target "Build" in project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp.sln".-- FAILED
Done building project "/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp.sln".-- FAILED

Build FAILED.
Errors:

/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp.sln (default targets) ->
(Build target) ->
/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/Microsoft.Build.Evaluation/Microsoft.Build.Evaluation.csproj (default targets) ->
/usr/lib/mono/4.5/Microsoft.Common.targets (PrepareForBuild target) ->

	: error : Error initializing task Message: Could not load file or assembly 'Microsoft.Build.Tasks.v4.0' or one of its dependencies. The system cannot find the file specified.

/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp.sln (default targets) ->
(Build target) ->
/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/Microsoft.Build.Evaluation/Microsoft.Build.Evaluation.csproj (default targets) ->
/usr/lib/mono/4.5/Microsoft.Common.targets (_RecordCleanFile target) ->

	: error : Error initializing task ReadLinesFromFile: Could not load file or assembly 'Microsoft.Build.Tasks.v4.0' or one of its dependencies. The system cannot find the file specified.

/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp.sln (default targets) ->
(Build target) ->
/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/NRefactory/ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj (default targets) ->
/usr/lib/mono/4.5/Microsoft.Common.targets (PrepareForBuild target) ->

	: error : Error initializing task Message: Could not load file or assembly 'Microsoft.Build.Tasks.v4.0' or one of its dependencies. The system cannot find the file specified.

/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp.sln (default targets) ->
(Build target) ->
/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/NRefactory/ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj (default targets) ->
/usr/lib/mono/4.5/Microsoft.Common.targets (_RecordCleanFile target) ->

	: error : Error initializing task ReadLinesFromFile: Could not load file or assembly 'Microsoft.Build.Tasks.v4.0' or one of its dependencies. The system cannot find the file specified.

	 0 Warning(s)
	 4 Error(s)

Time Elapsed 00:00:00.5894150

望 V 友们给个提示呗，这是啥错误啊，从哪里入手解决！

折腾了一下，决定不整了，记录一下我折腾的情况吧！

首先，发现自己装的时候装错了，我安装YCM的时候，用的是./install.py -all，这是默认安装所有特性，其中就包括了，C#的补全（./install.py --omnisharp-completer）而报错的这个OmniSharpServer库，正是C#的补全库！，什么鬼，Linux下写C#这种事情我根本不会干好伐！

但是觉得已经开搞了，不试着解决解决总是怪怪的，于是找了一下解决方案，发现我少装了两个包，又装了这么两个包 ！

sudo apt-get install libmono-microsoft-build-tasks-v4.0-4.0-cil
sudo apt-get install mono-dmcs

但是还是报错啊，错误是这样的：

/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp.sln (default targets) ->
(Build target) ->
/home/michael/Bundle/k-vim/bundle/YouCompleteMe/third_party/ycmd/third_party/OmniSharpServer/OmniSharp/OmniSharp.csproj (default targets) ->
/usr/lib/mono/4.5/Microsoft.CSharp.targets (CoreCompile target) ->

	: error CS8001: Warning as Error: SDK path could not be resolved

然后我就无解了，最终决定放弃，因为我根本不会在VIM中写C#啊，感觉自己真是闲的蛋疼！

[bwangel]

报错的编译命令是好长好长的一句， V2 贴不上来啊！

[dcoder]

@bwangel
所以我现在已经不用 YCM 了, 又肥又重又易出错...