I think that the code given in the documentation on "18.3. Embedding static elements in your application" is incorrect:

static GstPluginDesc plugin_desc = {
  GST_VERSION_MAJOR,
  GST_VERSION_MINOR,
  "my-private-plugins",
  "Private elements of my application",
  register_elements,
  NULL,
  "0.0.1",
  "LGPL",
  "my-application",
  "http://www.my-application.net/",
  GST_PADDING_INIT
};

GstPluginDesc should look like

typedef struct {
  gint major_version;
  gint minor_version;
  gchar *name;
  gchar *description;
  GstPluginInitFunc plugin_init;
  gchar *version;
  gchar *license;
  gchar *source;
  gchar *package;
  gchar *origin;

  gpointer _gst_reserved[GST_PADDING];
} GstPluginDesc;

This worked for me:

static GstPluginDesc plugin_desc = {
  GST_VERSION_MAJOR,
  GST_VERSION_MINOR,
  "my-private-plugins",
  "Private elements of my application",
  register_elements,
  "0.0.1",
  "LGPL",
  "source-module",
  "my-application",
  "http://www.my-application.net/",
  GST_PADDING_INIT
};