On Sat, 1/2/14, Donald Stufft <donald@stufft.io> wrote:
So perhaps it isn't that pip is lacking a useful feature, it's that pip tried it, as you did with distil, and due to pip's much larger user base it got a much more thorough real world experience with it and it turned out to be ultimately more trouble than it was worth? It could also have been a problem with how pip wrote it of course, and perhaps you've discovered a better way of writing it. However at the time it's obvious that the pain it was causing was enough to cause the pip developers to break backwards compatibility to remove that feature.
Why exactly was it removed? Well I can't find the reasoning beyond that commit so we'd need to get Carl or perhaps Jannis to come and tell us if they still remember. However it's clearly not that pip didn't just try or think of this, it did and it ultimately removed it.
Sure, and if they did find some problem which is also present in distil (i.e. due to a fundamental drawback of the approach) then I'll put my thinking cap back on. It'll be worth having that problem on record to avoid any repetition of work in the future. Regards, Vinay Sajip