500 when processing project.description via restructuredtext tag filter

[humitos]

Accessing https://readthedocs.org/projects/pydbgen/ you will get a 500.

The error happen because the title overline is not accurate:

SystemMessage: <string>:1: (SEVERE/4) Title overline & underline mismatch.

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Random database/dataframe generator
***************************************

The important code sections.

Template:

https://github.com/rtfd/readthedocs.org/blob/393e31ad3a9aafee297df64f1a654ffcda7ef04a/readthedocs/templates/core/project_details.html#L79-L83

Python code:

https://github.com/rtfd/readthedocs.org/blob/393e31ad3a9aafee297df64f1a654ffcda7ef04a/readthedocs/core/templatetags/core_tags.py#L45-L71

There is no feedback at all saying what's the error. Possible solutions:

• should fail silently, show the raw description and communicate the user with a message or
• do not parse it via restructuredtext at all

[davidfischer]

I made a small edit as this issue was referencing my fork of RTD.