My package github.com/me/foo is a module with a go.mod. It contains a require directive for github.com/thirdparty/bar, which imports github.com/thirdparty/baz (through an import in a .go file). However, bar is not a module, and doesn’t specify where to find baz.
How is baz resolved?
Would it use foo/go.mod? Would it use bar/go.mod, if it had one? Or does it only search GOPATH/GOROOT? I know foo has already downloaded baz to $GOPATH/pkg/mod. Does Go “know” it’s running from foo, and use foo's go.mod to resolve all import paths anywhere in its tree? What if a dependency wants to use its own version?