Eglot + gopls works fine.
I have the following in my init.el, and it works for installed packages (mod files)
(require 'project)
(defun project-find-go-module (dir)
(when-let ((root (locate-dominating-file dir "go.mod")))
(cons 'go-module root)))
(cl-defmethod project-root ((project (head go-module)))
(cdr project))
(add-hook 'project-find-functions #'project-find-go-module)
But when I end up visiting a file under /usr/local/go/src/
none of find-definition, find-references works.
Is there a way to make them work when you are outside of your project?
