Debian package: Missing dependency on Debian/etch

[[4-tea-2]]

Starting tahoe after upgrading a Debian/etch system to use the Debian Tahoe package 1.4.1-r3916 fails with this error message:

tahoe@{hostname}:~$ tahoe start
Traceback (most recent call last):
  File "/usr/bin/tahoe", line 2, in <module>
    from allmydata.scripts import runner
  File "/usr/lib/python2.5/site-packages/allmydata/scripts/runner.py", line 9, in <module>
    pkg_resources.require('allmydata-tahoe')
  File "/usr/lib/python2.5/site-packages/pkg_resources.py", line 626, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python2.5/site-packages/pkg_resources.py", line 524, in resolve
    raise DistributionNotFound(req)  # XXX put more info here
pkg_resources.DistributionNotFound: pysqlite>=2.0.5

Perhaps including python-pysqlite2 as a dependency in debian/control would fix this?

[[4-tea-2]]

Sorry, I forgot to mention that installing python-pysqlite2 manually fixed the problem.

[warner]

Hrm, on python2.5, it's not supposed to declare a dependency on pysqlite (since 2.5 comes with sqlite in the standard library).

Zooko?

[warner]

#728 was for adding this change. I grepped the current source code and the pysqlite requirement is guarded by an if sys.version_info < (2,5). Could you make sure that sys.version_info looks correct on your system, and that this conditional is doing the right thing?

[zooko]

Assigning to [4-tea-2] to investigate.

[warner]

Incidentally, when Zooko asked me about adding this dependency declaration, I agreed to it only with the condition that it not cause exactly this sort of problem (setuptools has taught me to not trust its dependency calculations: I am constantly seeing it rebuild things which are already installed). If this turns out to be some sort of deep problem, I'll recommend that we remove the declaration.

[zooko]

setuptools installs requirements that are already installed (#657 ("python ./setup.py test" rebuilds packages), #717 (unnecessary rebuild of dependencies when tahoe-deps/ is present)), but I don't think I've seen it install something which wasn't required. My guess is that [4-tea-2] installed a .deb which didn't declare a dependency on sqlite2 (possibly because the .deb is in error? Or because it was a .deb for python 2.6?), and then ran it with Python 2.5.

[4-tea-2]: which .deb of Tahoe-LAFS did you install?

Thanks!

[zooko]

Formatted original report with wiki quoting.