This is a demonstration of a post that does not render properly (the lack of hyperlink):
text text [logging module] (http://docs.python.org/library/logging.html). more text.
code code code
You'll want to drop that
To get this:
This looks like markdown doesn't want to parse links in a block immediately preceding a section surrounded by <pre> tags. Your [foo] label with footnote looks fine, and inserting one with the hyperlink WYSIWYG tool generates the same format (which also doesn't work).
I noticed you used <code> and <pre> tags -- it's generally easier to just indent your text by four spaces (which the binary button at the top of the editing window will do for you).
Here is a [link] that does not work... through experimentation, it would seem that it is the <pre> tag following that screws things up.
...stuff inside a pre tag
Here is a link that does work.
From what I see of your raw post text, you have not used valid Markdown.
Please refer to the editing help, which is linked: