dependency restrictions question

[ng0]

Hi,

packaging kallithea for Guix now moved to the QA phase and I have
further questions about it.

You have some strict dependencies on old or very old versions:
 - mercurial 3.7.3
 - dulwhich 0.9.9
 - routes 1.13
 - urlobject 2.3.4
 - docutils 0.11
 - markdown 2.2.1
 - babel 1.3
 - pyparsing 1.5.0

and at least one old version dependency which results from these old
package versions.

We like to keep the number of our old version in-tree packages
at a reasonable number, so my question is wether all of this is really
necessary or if someone has tested new versions of the packages
succesfully[0] and you just impose these restrictions because of
unspecified reasons.
If there are reasons, can you list them, if possible for every package I
named so that I can add the reason(s) as code-comment to the packages.

Thanks,


0: Even if it is considered unstable and experimental it would be an
improvement over adding all these old packages and we would be open to
considering the experimental path.
-- 
ng0 -- https://www.inventati.org/patternsinthechaos/