p.Dir = dir
				p.Root = root
				goto Found
			}
			tried.gopath = append(tried.gopath, dir)
		}

		// If we tried GOPATH first due to a "vendor/" prefix, fall back to GOPATH.
		// That way, the user can still get useful results from 'go list' for
		// standard-vendored paths passed on the command line.
		if ctxt.GOROOT != "" && tried.goroot == "" {
			dir := ctxt.joinPath(ctxt.GOROOT, "src", path)