%gopkginstall creates a .goipath file in %{buildroot}%{gopath}/%{goipath}/.goipath that contains some metadata that's used by the RPM generators later in the build process. These are not needed in the final package. They can sometimes cause conflicts when creating compat packages. The cause rpmlint warnings, as they're hidden files. It'd be better to mark them with %ghost so they're not included in the final package at all but still available for the generators.