如何在msbuild项目文件

Question

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <OutputType>Library</OutputType>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="FluentMigrator, Version=1.6.1.0, Culture=neutral, PublicKeyToken=aacfc7de5acabf05, processorArchitecture=MSIL">
      <HintPath>..\packages\FluentMigrator.1.6.1\lib\40\FluentMigrator.dll</HintPath>
      <Private>True</Private>
    </Reference>
  </ItemGroup>
  <ItemGroup>
    <Compile Include="FluentExtensions.cs" />
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
  <Target
    Name="Build2"
    Inputs="@(Compile)"
    Outputs="HelloWorld.dll"
  >
    <Csc
      OutputAssembly="HelloWorld.dll"
      Sources="@(Compile)"
      TargetType="library"
    />
 </Target>
</Project>

您好，为什么“Build”目标工作正常，但“Build2”说“CS0246：无法找到类型或命名空间名称'FluentMigrator'”？我应该在项目中包含哪些内容？我试图包括系统库，如System，System.Core，但没有效果。