is there a hg-download in Guix ?

I'd like to package python-suds as it was done in Fedora
https://koji.fedoraproject.org/koji/buildinfo?buildID=855311

The version packaged in Fedora is a single commit and then there's a patch
in an issue that solves a failure in the tests

The version in pypi is very old (hundreds of commits behind)

This package is a dependency for python-stdnum, that, in turn, is a
dependency for one of the Tryton modules (the module for accounting,
absolutely fundamental)

How do I solve this ?