[Distutils] Partial installs for in-process distribution upgrades (was: Installing packages using pip)

[Robert Collins]

On 10 December 2015 at 08:39, Erik Bray <erik.m.bray at gmail.com> wrote:
> Apologies for resending this--my original message got buried in
> unrelated commentary about how *nix filesystems work.  Resending with
> new subject line...

I think its going to break in nasty ways for users on Windows, on a
regular basis.

For instance: start two interpreters at once with a partially
installed thing present and watch them race.

For instance: put a .dll extension in a partially installed thing and
start a second interpreter without closing the one that triggered the
install. Watch the move error because the .dll is locked.

(And this is ignoring the questions around module namespaces in
sys.modules and the poorly-supported-in-practice semantics of
reload()).

-Rob