The following error is encountered when building ``Banshee.GStreamerSharp``::

    'Gst.List' does not contain a definition for 'FirstOrDefault' and no extension method 'FirstOrDefault' accepting a first argument of type 'Gst.List' could be found (are you missing a using directive or an assembly reference?) in
banshee\src\Backends\Banshee.GStreamerSharp\Banshee.GStreamerSharp\PlayerEngine.cs Line 182, Column 14

The FirstOrDefault extension method is provided by System.Linq (from the System.Core assembly), which is correctly referenced by the project.

Replacing the ``GetSubtitleDescription`` method of the ``PlayerEngine`` class with a loop allows the project to build correctly.

    Gst.List tag_list = playbin.GetTextTags (index)
        .GetTag (Gst.Tag.LanguageCode);
    foreach(string tag in tag_list)
    {
         if (tag != null)
         {
             return tag;
         }
    }
    return default(string); 

Another suggestion was to explicitly cast the list contents to ``string`` to allow the project to build::

    return playbin.GetTextTags(index)
        .GetTag(Gst.Tag.LanguageCode)
        .Cast<string>()
        .FirstOrDefault(t => t != null);