Proposed resolution (February, 2019):

Change 13.8.3.2 [temp.dep.type] bullet 6.3.2 as follows:

A name is a member of an unknown specialization if it is

• ...

• An id-expression denoting the member in a class member access expression (7.6.1.5 [expr.ref]) in which either

• the type of the object expression is the current instantiation, the current instantiation has at least one dependent base class, and name lookup of the id-expression does not find a member of a class that is the current instantiation or a non-dependent base class thereof; or

• the type of the object expression is type-dependent and is not the current instantiation.