<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'version'

Status changed to 'Confirmed' because the bug affects multiple users.

It seems that the python-apt assumption (apt.package.Package.is_upgradable and apt.package.Package.candidate is not None) seems to be not true in all cases. But why gets a package reported as upgradable but hasn't got a valid candidate at all?

Status changed to 'Confirmed' because the bug affects multiple users.

Especially every package without a candidate version seems to have this property set:

apt's depcache.cc around line 1500:
   if (Pkg->CurrentVer == 0 || Pkg->VersionList == 0 || CandidateVer == 0)
     Status = 2;

and
  inline bool Upgradable() const {return Status >= 1;};

which should probably be
  inline bool Upgradable() const {return Status >= 2 && CandidateVersion ;};

this would of course requires a rebuild of reverse dependencies and is probably not entirely correct either.

We could work around this in python-apt by checking that a candidate version exists for now, but this should be fixed in APT - if it's still broken, my local branch is not totally up-to-date.

I'm on i386 ver on precise and just got this problem after today's update.

Occurred only for the second time immediately after today's updates.

The attachment "fix-upgradable.patch" of this bug report has been identified as being a patch. The ubuntu-reviewers team has been subscribed to the bug report so that they can review the patch. In the event that this is in fact not a patch you can resolve this situation by removing the tag 'patch' from the bug report and editing the attachment so that it is not flagged as a patch. Additionally, if you are member of the ubuntu-reviewers team please also unsubscribe the team from this bug report.

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Fixed in python-apt 0.8.3-ubuntu6

Fix committed upstream in debian/experimental. Expect that to hit Ubuntu 16.04.

This bug was fixed in the package apt - 1.1.4

---------------
apt (1.1.4) unstable; urgency=medium

  [ Julian Andres Klode ]
  * defaults.mak: Set LC_COLLATE=C.UTF-8 for reproducible sort order
  * Avoid overflow when summing up file sizes

  [ David Kalnischkies ]
  * add a apt breaks (apt-utils << 1.1.3) for partial-upgrades (Closes: 806765)
  * require explicit paths to dsc/control as we do for deb files
    (Closes: 806693)
  * use @CHANGEPATH@ as placeholder in changelog URI templates
  * replace "which" with "command -v" for portability.
    Thanks to Mingye Wang for the suggestion. (Closes: 807144)
  * replace run-parts with find|sort to avoid debianutils usage
  * part revert, part redo 'which' replacement.
    Thanks to Jakub Wilk for pointing out #747320

  [ Fredrik Fornwall ]
  * apt-helper.cc: include <stdlib.h> for atoi (Closes: 807031)

 -- Julian Andres Klode <email address hidden> Mon, 07 Dec 2015 15:31:31 +0100