Adding gomock tests to project gives "build constraints exclude all Go files" when running test

Question

I add a test file for a package using gomock to an existing Go project, and now I am getting

...imports github.com/golang/mock: build constraints exclude all Go files in /home/bserdar/go/pkg/mod/github.com/golang/[email protected]

when I run go test from one of the packages using gomock. There are no build constraints in my project. Any idea what is wrong here?

Answer 1

It's not saying any files in your project are excluded, it specifically says all files in github.com/golang/mock are excluded, which is accurate; that's not an importable package, it doesn't contain anything. You should be importing the subpackages you need - or rather, per the documentation, you should be generating mocks using the tool, and the generated files should be importing valid packages.