[tahoe-lafs-trac-stream] [tahoe-lafs] #1452: clarify policy about what versions of dependencies Tahoe-LAFS requires

[tahoe-lafs]

#1452: clarify policy about what versions of dependencies Tahoe-LAFS requires
-------------------------------------------------+-------------------------
 Reporter:  zooko                                |          Owner:
     Type:  defect                               |  somebody
 Priority:  critical                             |         Status:  new
Component:  packaging                            |      Milestone:  soon
 Keywords:  packaging setuptools exocet testing  |  (release n/a)
                                                 |        Version:  1.8.2
                                                 |  Launchpad Bug:
-------------------------------------------------+-------------------------
 There are conflicting ideas about how tight the requirements Tahoe-LAFS
 should place on dependencies (in [source:src/allmydata/_auto_deps.py]).
 One way to do it would to be require versions of dependencies which we
 know work with Tahoe-LAFS (i.e. they don't have any critical bugs that are
 triggered by the way Tahoe-LAFS uses them nor fatal incompatibilities with
 Tahoe-LAFS or other code that Tahoe-LAFS uses). This would be the tightest
 policy. The other extreme—the loosest policy—is to allow any version
 unless we know for sure that particular version has a critical bug or
 incompatibility.

 I personally find it a bit dubious if we specify that Tahoe-LAFS requires
 a version of {{{Package X}}} greater than or equal to {{{Version N}}}, if
 we don't have any buildbots that have {{{Version N}}} installed. To me
 that sounds like we are claiming that Tahoe-LAFS will work with {{{Version
 N}}} of {{{Package X}}}, but making that claim without reproducible
 evidence that it is true. On the other hand we can just rely on the
 absence of any bug reports from the field which can be traced to a bug or
 incompatibility in some version of one of our dependencies.

 One possible future improvement would be to automate the testing of Tahoe-
 LAFS combined with different versions of dependencies. The exocet tool
 looks like it might facilitate that sort of work:
 [http://washort.twistedmatrix.com/2011/03/exocet-second-look.html Exocet:
 A Second Look]

 In the meantime, let's write down a policy on our Wiki and close this
 ticket.

 Another option would be to choose a set of operating systems/distributions
 that we think we should support and specify the versions of the
 dependencies which are provided in those. Currently we have the following
 operating systems/distributions in the Supported Builders category of our
 buildbot herd: Windows 7 x86_64, Debian 5 "Lenny" ("obsolete stable")
 x86_64, Ubuntu 10.04 "Lucid" x86_64, Ubuntu 10.10 "Maverick" x86_64,
 Debian 5 "Lenny" ("obsolete stable") x86, FreeBSD 8.2 x86_64, OpenBSD 4.8
 x86_64, NetBSD 5 x86, CentOS 5 (!RedHat 5.6) x86, Windows XP 5.1 SP 3 x86.

-- 
Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/1452>
tahoe-lafs <http://tahoe-lafs.org>
secure decentralized storage