Sphinx provides warnings about errors that it finds on lines etc when it parses pages. However, since we are parsing cell-by-cell, line numbers don't mean anything unless you know the cell they belong to.

We should find a way to get Sphinx to report not only line numbers, but cell numbers in the warning reporting.

It seems that the warning message itself gets raised after the parsing process...so it seems like there's something inside the Sphinx machinery making this happen as opposed to one of our parsers.