Command line builds using msbuild fail if not previously built in visual studio.

[mslagle]

The projects do not build using command line unless previously built in visual studio. Looking on the msbuild scripts, I have tracked it down to two targets failing to work.

_ComputeNonExistentFileProperty and CoreCompile.

Because I am not in visual studio, the _ComputeNonExistentFileProperty target never runs and thus I get the following issue:

Skipping target "CoreCompile" because it has no outputs.
Though the target has declared its outputs, the output specification only references empty properties and/or empty item lists.
Done building target "CoreCompile" in project "Project.javaproj".: (TargetId:42)

However, I feel like your logic for detecting the inputs and outputs for the target may be flawed since we are relying on a nonexistent file to not exist for the CoreCompile target to even run. You should probably build out the CompileOutputs itemgroup outside of the target instead of inside of it.