code: func (m *Meta) providerPluginSet() discovery.PluginMetaSet {
  	plugins := discovery.FindPlugins("provider", m.pluginDirs(true))
  
  	// Add providers defined in the legacy .terraformrc,
  	if m.PluginOverrides != nil {
  		for k, v := range m.PluginOverrides.Providers {
  			log.Printf("[DEBUG] found plugin override in .terraformrc: %q, %q", k, v)
  		}
  		plugins = plugins.OverridePaths(m.PluginOverrides.Providers)
  	}
  
  	plugins, _ = plugins.ValidateVersions()
  
  	for p := range plugins {
  		log.Printf("[DEBUG] found valid plugin: %q, %q, %q", p.Name, p.Version, p.Path)
  	}
  
  	return plugins
  }
docs: // providerPluginSet returns the set of valid providers that were discovered in
  // the defined search paths.