Visual Studio Online Build Fails on Dependent Project NuGet References - msbuild

Question

I am using Visual Studio Online for my repo and build. Here is my TFS hierarchy.
<ClassLibraries>
│
├───<Solution 1>
│ └───Build.Proj
│ └───.NuGet
│ └───NuGet.exe
│ └───NuGet.Config
│ └───NuGet.Targets
│ └───<Project 1> // Common Code
│ └───Project1.csproj
│ └───<Project 2> // Common Code Unit Test
│ └───Project2.csproj
│
├───<Solution 2>
│ └───Build.Proj
│ └───.NuGet
│ └───NuGet.exe
│ └───NuGet.Config
│ └───NuGet.Targets
│ └───<Project 3>
│ └───Project1.csproj
│ └───<Project 4>
│ └───Project2.csproj
I have a build definition for Solution 1 which builds succesfully, restoring the NuGet packages as required without issue.
The Solution 2.sln file includes Project 1 from Solution 1 as a dependency, as both Project 3 and Project 4 have code dependencies on it (Solution 1 is my common code solution, which is included in just about everything).
The build definition for Solution 2 fails because it cannot find the NuGet dependencies for Project 1. I guess the RestorePackages target in the Build.Proj is ignoring the dependent project.
<Target Name="RestorePackages">
<Exec Command="$(MSBuildThisFileDirectory).NuGet\NuGet.exe restore %(Solution.Identity)" />
</Target>
I can't fathom out why. If I execute "msbuild build.proj" locally on Solution 2 then it cleans and builds all projects succesfully.

Answer 1

I have worked out that my build.proj file needs to reference directly Solution 1 in this example:
<ItemGroup>
<Solution Include="$(MSBuildThisFileDirectory)*.sln" />
<Solution Include="$(MSBuildThisFileDirectory)..\Solution1\*.sln" />
</ItemGroup>
This then causes MSBuild to go through the NuGet package restore for the dependent project. Problem solved. Sort of..
After I had deleted all my local code and performed a Get Latest from the repo, I realised that VS2013 exhibits the behaviour I originally saw. So I need now to work out how to make the IDE build in the same way as the Build.Proj file I am using for VSO and msbuild executed from the command line.