On Mon, Jun 12, 2017 at 1:57 PM, Thomas Kluyver <tho...@kluyver.me.uk> wrote: > On Mon, Jun 12, 2017, at 09:45 PM, Daniel Holth wrote: > > I think all my wheel generators except bdist_wheel build the zipfile > directly. > > > There is a certain appeal to using the zipped .whl file as the canonical > format for all tools that produce or consume wheels, rather than defining a > closely related but distinct 'unpacked wheel' format. A directory and a zip > file do not have 100% identical features (filename encodings may differ, > entries in a zip file are ordered, there may be metadata in one format > that's not present in the other, and so on).
I find the reproducible builds argument to be a pretty compelling argument for generating wheels directly. (It also applies to sdists.) Another point is that tools that you might have in your build pipeline -- like auditwheel -- currently use wheel files as their interchange format, so you might end up having to zip, run auditwheel, unzip for pip, and the pip zips again to cache the wheel... The whole conversation feels a bit like we're falling into the developer trap of "oo there's a thing that might be optimizable therefore we MUST optimize it" without any real assessment of the benefits (I'm as guilty as anyone!). It's not even clear to me that copying a tree twice *is* faster than packing and then unpacking a wheel in general – if your tree consists of lots of small files and you're IO-bound, then the wheel version might well be faster. (E.g. on an underprovisioned virtual server, especially if using spinning media - while of course we're all benchmarking on laptops with fast SSD and everything in cache :-).) And in any case, I'm generally very skeptical of moving away from the well-specified wheel format that already has lots of tooling and consensus around it towards anything ad hoc, when AFAICT no-one has even identified this as an important bottleneck. -n -- Nathaniel J. Smith -- https://vorpus.org _______________________________________________ Distutils-SIG maillist - Distutils-SIG@python.org https://mail.python.org/mailman/listinfo/distutils-sig
