Antoine Pitrou writes:
And in fact this case is often more the important one. Packages that depend on having a *recent* version of python will often crash quickly, before doing permanent damage, when an undefined syntax, function, or method is invoked, while packages that depend on a quirk in behavior of an older version will typically silently corrupt data.
How can they know that they depend on "a quirk in behaviour of an older version" if a newer version hasn't been released? This sounds bogus.
Of course a newer version has been released. Who said it hasn't been? Eg, the discussion of <=2.5. Hasn't 2.6 been released? Or am I hallucinating? The point is that some packages depend on >=2.5, and others depend on <=2.5. I see no reason to deprecate the "<=" notation.