code: func isMaybeRelativeLocalPath(addr, dir string) bool {
  	for _, prefix := range localSourcePrefixes {
  		if strings.HasPrefix(addr, prefix) {
  			// it is _definitely_ a relative path
  			return false
  		}
  	}
  
  	_, err := regsrc.ParseModuleSource(addr)
  	if err == nil {
  		// it is a registry source
  		return false
  	}
  
  	possibleRelPath := filepath.Join(dir, addr)
  	_, err = os.Stat(possibleRelPath)
  	if err == nil {
  		// If there is no error, something exists at what would be the relative
  		// path, if the module source started with ./
  		return true
  	}
  
  	return false
  }
docs: // isMaybeRelativeLocalPath tries to catch situations where a module source is
  // an improperly-referenced relative path, such as "module" instead of
  // "./module". This is a simple check that could return a false positive in the
  // unlikely-yet-plausible case that a module source is for eg. a github
  // repository that also looks exactly like an existing relative path. This
  // should only be used to return a warning.