I do not know whether this would be a new question — but it would seem that this issue should be cross posted with Multi-line comments on Stack Overflow.
If you do think that this should be a new question, I have expanded it to a full new question here to actually include details that are not directly relevant to this local concern.
Currently there is no system for properly formatting code left in comments. I have to point out that if the consensus is that code in comments is ever useful, even if the goal is to dissuade people from posting long chunks of code into comments, wouldn't it be desirable to have proper line-breaks and other simple formatting options (optional syntax highlighting) for code snippets that are not too many lines long.
New python executables in MYENV/bin/python3.4
Also creating executable in MYENV/bin/python
Installing setuptools, pip, wheel...done.`
is much easier to read than `> New python executables in MYENV/bin/python3.4 > Also creating executable in MYENV/bin/python > Installing setuptools, pip, wheel...done.`
And I'd much have preferred to write that (here). And it would not have taken up much more space compared to other comments. So legibility suggests that better formatting for those shorter code snippets should be desirable if it is recognized that code snippets should be well designed.
Furthermore — that concern – I'd argue – should win over a theoretical concern raised in the crosslinked post which shifted a discussion about multi-line comments to the appropriateness of including code in comments in the particular case where you are writing modifications of example code from the post. However, this use case does not cover all the kinds of instances where code formatting would be useful.
From the perspective of this question's point of not wanting to encourage long comments filled with illegible code that skewed the display of the comment section, you could put an upper limit on numbers of lines allowed (at least 5 total would make it no longer than the max of the current comments), and if the warning is instituted in the form as it is described here, it could additionally warn people if they exceed some threshold of character density.
So in that sense, it seems like this warning is worthwhile, however, for the things that don't trigger the warning, there should be a better method for formatting them. Currently they are far too hard to read. Scaling Consolas down to 11 pts might make it a little hard to read…
…but I will leave those details and related concerns to the other question that I'll ask here (link to come).
But I do believe that the answer I provide here is providing a unique, relevant set of insights that answer this particular question at large which is regarding how to prevent unreadable segments of code in comments. It is relevant because it provides a further provision regarding the kinds of situations that will be needed to be considered as part of the described warning for difficult to read code snippets.
And certainly if we are to consider with any prejudice the perspective induced from the title as being the abstract "code in comments", I think we all can agree that the concern about how we format that code which is sanctioned by silence (non-warning) in comments is almost surely relevant to the general concern of code in comments. If this is not intended to be a general discussion of those policies, I think there should be a change to the title to better reflect the exact content intended for this discussion to proceed.
Also it is unclear whether this information has been updated to account for any features actually implemented regarding this discussion, since that request for a feature seems to have been made ~2.75 years ago. If anything has been implemented regarding this, it would be good to see it expressed in the original question.