The compilation time can be improved. Run "dotnet build --build-profile" for more information

Question

I'm in VS 2015 Update 3, Windows 10, .NET Core 1.0. When I build a project in my solution, I receive the message in the title:

(The compilation time can be improved. Run "dotnet build --build-profile" for more information)

When I run that in any of the projects, however, I get this:

Project MyProj.Web (.NETCoreApp,Version=v1.0) was previously compiled. Skipping compilation.

If I clean the solution and delete all bin and obj folders, that command builds the project like normal with no extra info printed as a result of the --build-profile flag. Builds in Visual Studio after that still print the message.

Is there something I should be doing to rectify this?

Answer 1

It seems that MSBuild is working as designed here. It doesn't build the project because nothing in the source has changed to require a rebuild. It will give you this message to notify you, in case there is some change made that MSBuild didn't detect.

This message can be a bit confusing, see this issue on github for more details about this behavior.