You need to create Google API key and build multimedia/minitube with that, inserting
If installing: Google is now requiring an API key in order to access YouTube Data web services. To obtain a key: 1. Create a new project at https://console.developers.google.com/ 2. Select newly created project and go to Enable API, go to APIs & auth / APIs, select the Youtube Data API and click Enable. 3. Go to Credentials, click Create Credentials and choose API key. 4. If you are going to build minitube from ports, set MINITUBE_GOOGLE_API_KEY=your_key in make.conf. If you use package set GOOGLE_API_KEY environment variable to your key.