'dotnet build' specify main method

Question

I am using dotnet to build a .NET Core C# project from the command line. The project has multiple classes with a main method. Thus I get the error:

Answer 1

You can edit your csproj to define which class to use (inside a PropertyGroup):

foo.Program2

or specify this MSBuild property on the command line via:

$ dotnet build foo.csproj /p:StartupObject=foo.Program2