Why do the URLs of posts here change?

[Peter Otten]

Steven D'Aprano wrote:

> I have come across this in the past, but today it annoyed me enough that
> I'm asking for an explanation.
> 
> Posts on this newsgroup/mailing list are archived on the web, but the URLs
> seem to change, which leaves dead links if you search for things.
> 
> For example, today I searched for a quote about floating point equality by
> William Kahan, and I came across this post by me:
> 
> https://mail.python.org/pipermail/python-list/2008-February/468598.html
> 
> But that's a dead link! Here's Google's cache of it:
> 
> 
http://webcache.googleusercontent.com/search?client=opera&rls=en&q=cache:i0cWb0Tjxe0J:https://mail.python.org/pipermail/python-list/2008-February/468598.html%2Bfloating+point+superstition+equality&oe=utf-8&channel=suggest&gws_rd=ssl&hl=en&&ct=clnk
> 
> And here is the actual URL, as it appears today:
> 
> https://mail.python.org/pipermail/python-list/2008-February/481374.html
> 
> 
> Why has the URL changed? Surely this is a bug? Where can I report it?

This is a flaw of the mailman software.

http://wiki.list.org/display/DEV/Stable+URLs

suggests that the developers are aware of it. 

I don't know if there is a version available that has stable urls...