[Distutils] additional paths in wheel

[Daniel Holth]

On Thu, Sep 4, 2014 at 2:55 PM, Donald Stufft <donald at stufft.io> wrote:
>
> On Sep 4, 2014, at 1:58 PM, Daniel Holth <dholth at gmail.com> wrote:
>
> It's always been obvious that wheel would probably need additional
> paths besides the sysconfig ones, and there's been some discussion
> here recently.
>
> For the next version we should:
>
>
> The next version of the Wheel spec?

This would be Wheel 2.

It would still include WHEEL with the file format version, older
clients would be able to show the error.

Why allow paths to be written in a .py? The .py would be purely
declarative; it would allow a program to find its files without using
any pkg_resources API. IMO it's important to allow programs to work
without iterating over the metadata of all installed packages or
without participating in the package management system at all.

# possibly only the paths that were actually used...
paths = { 'prefix':'/usr/local/', 'bindir':'/usr/local/bin' , ...}
# OR
PREFIX="/usr/local"
BINDIR="/usr/local/bin"
MANDIR="/usr/local/share/man/..."

> 1. Add the autoconf dirs.
> https://www.gnu.org/prep/standards/html_node/Directory-Variables.html.
> "packagename-1.0/data/dvidir/" or any of the other autoconf paths
> would be valid, in addition to the existing distutils paths. (The
> autoconf paths are defined relative to a $prefix, in Python's case
> $prefix is usually the base of the virtualenv).
>
>
> Sounds plausible.
>
>
> 2. Replace WHEEL with wheel.json. wheel.json contains all the
> information from WHEEL but is json which is rather popular these days.
>
> wheel.json may contain custom paths with string Template() interpolation.
>
> { "paths": "name":"$prefix/mypath", "othername":"$bindir/etc",
> "thirdname": "$othername/subfolder" }
>
> (the sysconfig names, autoconf names, and custom path names can be
> interpolated here)
>
>
> I don’t understand this paths stuff, what is it supposed to be doing

Instead of just having predefined paths in the
packagename-1.0.data/[path] directories, the user could define
additional values for "path" in the {"path" : "installation
directory"} dictionary used by wheel installers. (I'm not 100% sure
this proposed feature does not cause more problems than it solves...)

> Also with JSON, the problem is the current tooling is now setup to
> handle a key: value WHEEL store, so we’ll need some sort of a migration
> path for old tools to know that this is a Wheel they can’t handle. It’s
> possible that it’s not worth it to do this.

They would just contain a stub WHEEL advertising version 2.

> ---
> Donald Stufft
> PGP: 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA
>