With CPython switching to GitHub for repository management and code
review, while retaining Roundup for issue tracking, the lack of markup
support on the issue tracker is become a more noticeable limitation.

For another Python based project (https://beaker-project.org) we were
entirely happy with https://pypi.org/project/Markdown/ as an option for
adding basic markup support that enabled bulleted lists, italics, bold
text, monospace text, and pre-formatted 

There are also a couple of libraries that add support for GitHub's
markdown enhancements (like fenced code blocks that don't require
indentation changes):

* https://pypi.python.org/pypi/gfm/ (preprocessor based approach)
* https://pypi.python.org/pypi/py-gfm (markdown extension based approach)

(Note: I also filed an wishlist item for this directly against the
meta-tracker for the PSF's downstream Roundup instance:
psf.upfronthosting.co.za/roundup/meta/issue626 )