Fair enough. I clarified because the days of editing code in some dependency of yours are over; it's not easily exposed for that purpose (but you can do it ;).
Which is, of course, totally unacceptable. This is a critical use case for doing deep-dive debugging or for code exploration. Fortunately for us there is the wonderfully named "gohack", which does easily expose your deps for editing (though not as easily as before): https://github.com/rogpeppe/gohack