[Distutils] PEP 440 and direct references

[Nick Coghlan]

On 27 June 2013 13:12, PJ Eby <pje at telecommunity.com> wrote:
> On Wed, Jun 26, 2013 at 1:40 PM, Vinay Sajip <vinay_sajip at yahoo.co.uk> wrote:
>>   (a) Repeatability (not possible with a generic "latest version" URL).
>
> ISTM that forcing repeatability in the spec implies the inability to
> do development with requirements that are also in development, unless
> there is also an out-of-band channel for communicating the URL.

Yeah, I think you might be right here. Specific tools that want to
ensure repeatability are free to impose restrictions like that (just
as they're free to rule out the use of direct references entirely),
but we don't want to constraint them too much at the specification
level or they lose their effectiveness as an escape clause.

The description already says "The exact URLs and targets supported
will be tool dependent."

I think it's OK for distlib to require that by the time any associated
info is handed over as a requirements specification, it has been
converted to a specific version number. It isn't distlib's problem
whether that was extracted from the URL directly, or by downloading it
and looking at (or possibly even generating) the metadata.

Cheers,
Nick.

--
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia