On 15 February 2017 at 12:58, Nathaniel Smith <n...@pobox.com> wrote: > On Wed, Feb 15, 2017 at 3:33 AM, Nick Coghlan <ncogh...@gmail.com> wrote: >> - "requires": list where entries are either a string containing a PEP >> 508 dependency specifier or else a hash map contain a "requires" key >> plus "extra" or "environment" fields as qualifiers >> - "integrates": replacement for "meta_requires" that only allows >> pinned dependencies (i.e. hash maps with "name" & "version" fields, or >> direct URL references, rather than a general PEP 508 specifier as a >> string) > > What's accomplished by separating these? I really think we should > strive to have fewer more orthogonal concepts whenever possible...
It's mainly a matter of incorporating https://caremad.io/posts/2013/07/setup-vs-requirement/ into the core data model, as this distinction between abstract development dependencies and concrete deployment dependencies is incredibly important for any scenario that involves publisher-redistributor-consumer chains, but is entirely non-obvious to folks that are only familiar with the publisher-consumer case that comes up during development-for-personal-and-open-source-use. One particular area where this is problematic is in the widespread advice "always pin your dependencies" which is usually presented without the all important "for application or service deployment" qualifier. As a first approximation: pinning-for-app-or-service-deployment == good, pinning-for-local-testing == good, pinning-for-library-or-framework-publication-to-PyPI == bad. pipenv borrows the Ruby solution to modeling this by having Pipfile for abstract dependency declarations and Pipfile.lock for concrete integration testing ones, so the idea here is to propagate that model to pydist.json by separating the "requires" field with abstract development dependencies from the "integrates" field with concrete deployment dependencies. In the vast majority of publication-to-PyPi cases people won't need the "integrates" field, since what they're publishing on PyPI will just be their abstract dependencies, and any warning against using "==" will recommend using "~=" or ">=" instead. But there *are* legitimate uses of pinning-for-publication (like the PyObjC metapackage bundling all its subcomponents, or when building for private deployment infastructure), so there needs to be a way to represent "Yes, I'm pinning this dependency for publication, and I'm aware of the significance of doing so" Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ Distutils-SIG maillist - Distutils-SIG@python.org https://mail.python.org/mailman/listinfo/distutils-sig