Bug#728274: python-apt: apt.conf used from /etc/apt instead of root_dir + etc/apt

[Thomas Bechtold <thomasbechtold@jpberlin.de>]

Package: python-apt
Version: 0.9.1
Severity: normal

Dear Maintainer,

I tried to use python-apt to get all available package versions. I used
the 'rootdir' parameter for apt.Cache to have a seperate root dir and
seperated config files.
In my /etc/apt/apt.conf , I have the following line:

APT::Default-Release "sid";

In my root-dir, I create an empty 'rootdir/etc/apt/apt.conf' and when I
try to init the apt.Cache, I get the following error:

Traceback (most recent call last):
  File "./python-apt-repro-test", line 31, in <module>
    cache = apt.Cache(rootdir=root_dir, memonly=False)
  File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 105, in __init__
    self.open(progress)
  File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 150, in open
    self._cache = apt_pkg.Cache(progress)
SystemError: E:The value 'sid' is invalid for APT::Default-Release as such a release is not available in the sources


Attached is a test program which results in this error (but you have add
the "APT::Default-Release" line to your /etc/apt/apt.conf).


Cheers,

Tom


-- System Information:
Debian Release: jessie/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.10-3-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages python-apt depends on:
ii  libapt-inst1.5     0.9.12.1
ii  libapt-pkg4.12     0.9.12.1
ii  libc6              2.17-93
ii  libgcc1            1:4.8.2-1
ii  libstdc++6         4.8.2-1
ii  python             2.7.5-5
ii  python-apt-common  0.9.1

Versions of packages python-apt recommends:
ii  iso-codes    3.47-1
ii  lsb-release  4.1+Debian12
ii  xz-utils     5.1.1alpha+20120614-2

Versions of packages python-apt suggests:
pn  python-apt-dbg  <none>
ii  python-apt-doc  0.9.1
ii  python-gtk2     2.24.0-3+b1
ii  python-vte      1:0.28.2-5

-- no debconf information

#!/usr/bin/python
# Author: Thomas Bechtold <thomasbechtold@jpberlin.de>

import apt
import apt_pkg
import os
import tempfile

apt_pkg.init()
SOURCES_LIST = """
deb [arch=amd64,i386] http://ftp.debian.org/debian/ sid main
"""

try:
    #create a tempdir for the sources.list
    root_dir = tempfile.mkdtemp(prefix='python-apt-repos-test_')
    print "rootdir is: '%s'" % (root_dir)
    #create sources.list
    os.makedirs(os.path.abspath(root_dir + "/etc/apt"))
    with open(os.path.abspath(root_dir + "/etc/apt/sources.list"),
              "w") as s:
        s.write(SOURCES_LIST)
    #create empty apt.conf and apt.conf.d
    os.makedirs(os.path.abspath(root_dir + "/etc/apt/apt.conf.d"))
    with open(os.path.abspath(root_dir + "/etc/apt/apt.conf"),
              "w") as s:
        s.write("")

    #Here, the file /etc/apt/apt.conf is used to get "APT::Default-Release"
    # but expected is that rootdir + etc/apt/apt.conf is used
    cache = apt.Cache(rootdir=root_dir, memonly=False)

finally:
    pass
    #import shutil
    #shutil.rmtree(root_dir)