On Tue, Aug 28, 2012 at 6:29 AM, "Martin v. Löwis" <mar...@v.loewis.de> wrote: > Am 27.08.12 16:56, schrieb Daniel Holth: >> Metadata 1.2 is nearly 8 years old and it's Accepted but not Final. Is >> it better to continue editing it, or create a new PEP for Metadata >> 1.3? > > > You can't add new fields to the format after the fact, unless the format had > provided for such additions (which it does not - there is > no mention of custom fields anywhere, and no elaboration on how > "unknown" fields should be processed). > > So if you want to add new fields, you need to create a new version > of the metadata.
I agree with this point - the main reason the metadata PEP is still lingering at Accepted rather than Final is the tangled relationship between distutils and other projects that led to the complete distutils feature freeze. Until distutils2 makes it into the standard library as the packaging module, the standard library is going to be stuck at v1.1 of the metadata format. > Prepare for a ten-year period of acceptance - so it > would be good to be sure that no further additions are desired within > the next ten years before seeking approval for the PEP. However, this point I really don't agree with. The packaging ecosystem is currently evolving outside the standard library, but the standardisation process for the data interchange formats still falls under the authority of python-dev and the PEP process. If there are things missing from v1.2 of the metadata spec, then define v1.3 to address those known problems. Don't overengineer it in an attempt to anticipate every possible need that might come in the next decade. Tools outside the standard library are then free to adopt the new standard, even while the stdlib itself continues to lag behind. When the packaging module is finally added (hopefully 3.4, even if that means we have to temporarily cull the entire compiler subpackage), it will handle the most recent accepted version of the metadata format (as well as any previous versions). If more holes reveal themselves in the next 18 months, then it's OK if v1.4 is created when it becomes clear that it's necessary. At the very least, something v1.3 should make explicit is that custom metadata should NOT be put into the .dist-info/METADATA (PEP 376 location, PKG-INFO, in distutils terms) file. Instead, that data should be placed in a *separate* file in the .dist-info directory. Something that *may* be appropriate is a new field in METADATA that explicitly calls out such custom metadata files by naming the PyPI distribution that is the authority for the relevant format (e.g. "Custom-Metadata: wheel" to indicate that 'wheel' defined metadata is present) Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
