HintPath and Team Build

Very long week so I've got to keep this short. For some reason when a developer added a Reference to his csproj file it didn't add a <HintPath. The build worked locally and it worked on the build machine when we ran the build manually through Visual Studio. However, when trying to run the build via Team Build, we got the error "Could not resolve this reference. Could not locate the assembly." We could see that when Csc.exe was called, our Reference was not referenced.

The fix was to add a <HintPath to the csproj file. After doing that, Team Build ran fine and we could see it added to the Csc.exe Reference command line. I didn't get time to figure out why, but thought I'd document it here for when it happens again.