New submission from Zooko O'Whielacronx <zooko@zooko.com>: There is a bug which manifests itself if you combine Twisted v8.1.0 with pyOpenSSL v0.7. It doesn't happen with pyOpenSSL v0.6. However, the bug is a bug in Twisted, not in pyOpenSSL. Future releases of Twisted will probably fix the bug. Future releases of pyOpenSSL will probably be unchanged with respect to this issue. So the right way for the foolscap project to express its dependency on Twisted and pyOpenSSL should probably be something like: (Twisted < 8.2 && pyOpenSSL == 0.6) || (Twisted >= 8.2 && pyOpenSSL >= 0.7) Since setuptools doesn't currently support expression of such requirements, the foolscap author is going to write: ['Twisted', 'pyOpenSSL == 0.6'] Thus preventing people from using a newer version of pyOpenSSL with foolscap until Twisted is fixed, then the author of foolscap learns that Twisted is fixed, then he changes his requirements to ['Twisted >= $FIXED_VER', 'pyOpenSSL

= 0.6'], then he releases a new release of foolscap, then people upgrade to it.

So this wishlist item is for setuptools to develop the ability to express requirements on combinations of packages so that the correct dependency (the first one listed above) can be expressed. ---------- messages: 39 nosy: zooko priority: wish status: unread title: wish: more expressive requirements _______________________________________________ Setuptools tracker <setuptools@bugs.python.org> <http://bugs.python.org/setuptools/issue22> _______________________________________________