Wouldn't the provides line needs a full path, otherwise, it could conflict?

I'm generally against this proposal. One of the reasons I like using a distribution like Fedora is for dependency convergence. And I prefer exceptions to be rare and carefully deliberated.

That said, where I think this could really help as a blanket policy change is when it applies to bundled resources for web apps, like JavaScript libraries. Those are often very hard to split out from the upstream build, the web apps tend to rely on specific versions unique to that app, and linking to a system-provided version tends to require drastic changes to upstream code to change its resource-loading mechanisms.

[Apologies for top posting; on mobile]


On Thu, Sep 10, 2015, 09:53 Stephen Gallagher <sgallagh@redhat.com> wrote:
I assume that subject line got your attention.

I know this is a long-standing debate and that this thread is likely
to turn into an incomprehensible flamewar filled with the same tired
arguments, but I'm going to make a proposal and then attempt to
respond to many of those known arguments up-front (in the hopes that
we can try to keep the conversation on-track). Please keep the
conversation on devel@lists.fedoraproject.org . I CCed packaging@ to
make them aware of this discussion.



Right now, we have a policy that essentially forbids source code from
being bundled into a package. In technical terms, this means
essentially that the packaging policies mandate that any code that
appears more than once in the repository must be turned into a shared
library and dynamically linked into any package that requires it. Any
package that wants an exception to this must petition the Fedora
Packaging Committee and get an explicit exemption from this policy.
This process is heavyweight and sometimes inconsistent in how the
decision is made.

I would like to propose that the no-bundled-libraries policy be
amended  as follows: "Any package that has an existing mechanism to
link against a shared system library and functions correctly when
doing so must link against that library and not bundle it internally.
Any package whose upstream releases cannot link against a shared
system library (or are incompatible with the version in Fedora) may
bundle that library (without requiring a special exemption) but MUST
add Provides: bundled(<libname>) = <version> in the spec file for each
known bundled library.(This will allow us to track down the bundling
when we need to). Package maintainers should continue attempt to
engage upstream to support linking against shared system libraries
wherever possible, due to the advantages it provides the package
maintainer."



The reason for this proposal is relatively simple: we know the
advantages to unbundling, particularly with security and resource-
usage. However, the world's developer community largely *does not
care*. We fought the good fight, we tried to bring people around to
seeing our reasoning and we failed.


The point of software is to provide a service to an end-user. Users
don't run software because it has good packaging policies, they run
software because it meets a need that they have. If they can't get
that software from Fedora, they *will* get it from another source (or
use a different OS that doesn't get in their way). I'll take a moment
to remind people that two of Fedora's Four Foundations are "Features"
and "First". We want Fedora to be the most feature-complete
distribution available and we want to get there before anyone else
does. I would say that holding to our no-bundling policy actively
defeats our efforts on that score.



Let me describe some of the advantages to bundling and to unbundling
(as noted so we can hopefully skip some of the hotter parts of the
flamewar). As I noted above, anything that is capable of unbundling
should remain unbundled for its advantages. But things that are not
currently capable (or can't be due to forwards/backwards compatibility
issues, etc.) really shouldn't be forced to attempt it.


== Advantages to using shared libraries ==
 * Security/Bugs - When a bug or security vulnerability is located in
a library, it needs to be patched in only a single package in order to
fix all applications using that library.
 * Resources - A shared library only needs to be loaded into memory
once, reducing the memory requirements of the system.

== Advantages to bundling ==
 * Guarantees that the application is running with the same set of
code that upstream tested. (Fewer Fedora-specific bugs means less
burden on the maintainer)
 * Simplifies packaging of updates. (Fedora maintainer does not need
to keep tabs on unbundling patches to keep in sync for new versions)
 * Increases the available pool of software that can be packaged
substantially (many modern languages such as Ruby and Go are
realistically only functional with allowable bundling)
 * Did I mention the reduction in maintainer burden yet?




Thank you for reading this far. I know that this is a topic that
people get highly passionate about, so please do your best to restrain
your responses to reasoned statments and avoid the temptation to get
angry. I'll summon up a third of our Four Foundations here: remember
that Fedora is built on "Friends" too. This should be a discussion and
not an argument.--
devel mailing list
devel@lists.fedoraproject.org
https://admin.fedoraproject.org/mailman/listinfo/devel
Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct