View reverse relationship to taxonomy vocabulary reference field is broken

Create an entity reference field of type "Taxonomy vocabulary". Then create a taxonomy view, and try to add a relationship to the referencing entity that connects to that field - the label will be something like "A bridge to the Content entity that is referencing Taxonomy vocabulary via field_yourfieldname". The query that Views creates is broken, because Views does not define the necessary information about the taxonomy_vocabulary table - it has no "base" information, because you can't create a view on vocabularies.

The result is that it tries to join to taxonomy_vocabulary. and you get an error like this

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '= field_data_field_yourfieldname.field_yourfieldname_target_id AND (field_data_field_yourfieldname' at line 2

The field name is missing because views_handler_relationship_entity_reverse->query() assumes that it can get it from ['table']['base']['field'], which in this case is undefined. That also produces a PHP error:

Notice: Undefined index: base in views_handler_relationship_entity_reverse->query() (line 28 of /path/to/your/docroot/sites/all/modules/views/modules/field/views_handler_relationship_entity_reverse.inc).

I'm not sure where or how to fix this. The simplest thing is to patch Views to add base information for taxonomy_vocabulary but that's not a real solution. I don't know if there is a way to override or extend the base Views code so that Entity Reference can make it work.