[Distutils] PEP 517: Open questions around artifact export directories

[C Anthony Risinger]

On Tue, Jun 13, 2017 at 8:53 PM, Nick Coghlan <ncoghlan at gmail.com> wrote:

> On 13 June 2017 at 19:44, Thomas Kluyver <thomas at kluyver.me.uk> wrote:
> > On Tue, Jun 13, 2017, at 02:27 AM, Nick Coghlan wrote:
>
> > I've updated the PR to specify zip archives for build_wheel and .tar.gz
> > archives for build_sdist.
>
> +1
>
> I've added one suggestion, which is to explicitly require PAX_FORMAT
> for the sdist tarballs produced this way (that's a POSIX format
> standardised in 2001 and supported by both 2.7 and 3.x that
> specifically requires that the paths be encoded as UTF-8). While the
> standard library does still default to GNU_FORMAT in general, the
> stated rationale for doing so (it being more widely supported than
> PAX_FORMAT) was last updated more than 10 years ago, and I don't think
> it applies here.


I'm not trying to open a bikeshedding opportunity here -- and I tried to
ignore it, honest! -- but why are tarballs preferable to zipfiles for
sdists?

I looked around the 517 threads to see if it had been covered already, and
all I found was that zipfiles have additional PKG-INFO expectations in
existing implementations, and other honorable mentions of their features
over tarballs.

I've never understood the anti-affinity towards zip because the format
itself seems superior in many ways, such as the ability to easily append or
replace-via-append (which might actually help perf when being used as an
interchange format, with a repack/prune at the end), compress individual
files, and the brilliance of placing the central directory/manifest at the
end, allowing it to be appended to binaries, etc. and allowing rapid
indexing of files. Tarballs are a black box.

Just seems a little odd/arbitrary to me that wheel is zip, python supports
zip importing, sdists are often zip, and Windows is zip-central, but we'd
decide to codify tar.gz. It doesn't affect me personally because I'm Linux
all the way down and barely remember how to use Windows, but with all the
existing zip usage, and technical superiority(?), if we are going to pick
something, why not that? At that point Python is all-zip and no-tar.

It's not a strong opinion really, but since the PEP does attempt to limit
what's currently possible, can we add some verbiage as to why tar.gz is
preferred? Or consider it with more scrutiny?

-- 

C Anthony
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/distutils-sig/attachments/20170615/85592339/attachment-0001.html>