Duplicate target name, cannot be used as a unique reference:

[bradley...@gmail.com]

Suppose that the file index.rst contains the text below. This results (for me) in the error message above. In addition the local table off contents has variable_name for the link to the heading variable_name_. Is this expected  and if so, how should one document a case like this ?

Test Headings
#############

.. contents::
:local:

Arguments to Constructor
************************

variable_name
=============
Discussion of this argument

Memember Variables
******************

variable_name_
==============
Discussion of this member variable

[bradley...@gmail.com]

It appears that Sphinx does not work with headings that have a underbar at the end ? It this is the case, a better warning message would be helpful.