I have a simple console app in .net core and I try to compile it with "dotnet build dirs.proj" but "I get : error MSB4057: The target "Build" does not exist in the project."

If anyone has any idea, please share your thoughts!

This is the dirs.proj, it is quite simple.

The targets file does not have the Build defined. However, if I define something that's like it does not do anything.

Thanks in advance for any idea or example.