From: Alexis Métaireau firstname.lastname@example.org On 12/21/2010 09:41 PM, Sridhar Ratnakumar wrote:
- Did anyone--Alexis and Tarek, in particular--think of real-world use
cases for virtual projects (and even "provides" in general) other than the Zope transaction case? If yes, what are they?
"Provides-Release" lists the specific projects provided with this distribution. One case I can think about is having a distribution providing two different projects.
A software can have a project for the "core" features and a project for the "default-plugins". It can then provides the two projects in only one distribution.
Those can be two virtual projects 'core' and 'defaultplugins', which can be *provided* by different projects then. This allows to choose between the possible projects when resolving the dependencies.
What is the benefit of distributing two projects in a single distribution, compared to the more simpler (traditional) solution of distributing them in separate distributions (and, optionally, making one depend on another; eg: 'core' depend on 'defaultplugins')? Does this benefit justify the cost of introducing a new metadata field?
setuptools and distribute can be both provided by the same virtual project.
Is this the only real-world use of virtual projects? Are there (potential) others?
- Personally, I have needs for "virtual" packages from a binary (not
source) distribution perspective. For example, "MySQL-python" can be a virtual package "provided by" the binary distributions: mysql5.1-python, mysql5.0-python;
How would PEP 345's "Provides-Release" help, if at all, in describing this scenario?
I'm not sure it will help in this case, unfortunately.