Ignore explicitly relative 'from' imports when scanning for dependencies

[Michael Terry]

===== SRU Justification =====

This causes a bad bug in Quickly (bug 775217). Basically, "quickly package" shows errors and suggests to the user that continuing is not safe. It is a bad user experience and a regression from past releases.

I wrote this patch here during natty's development to fix it, but it didn't make it in.

The attached debdiff will backport the upstream commit to natty's version of python-distutils-extra. I've uploaded it to natty-proposed as well.

To reproduce:
1) cd /tmp
2) quickly create ubuntu-application test-project
3) cd test-project
4) quickly package

What you see:
"""
----------------------------------
Command returned some ERRORS:
----------------------------------
ERROR: Python module test_projectconfig not found
ERROR: Python module Builder not found
ERROR: Python module helpers not found
ERROR: Python module preferences not found
ERROR: Python module Window not found
----------------------------------
Do you want to continue (this is not safe!)? y/[n]:
"""

What you should see:
"""Ubuntu package has been successfully created in ../test-project_0.1_all.deb"""

=============================

Submodules of a program may use relative imports. These should not be treated as dependency-generating imports that cause either printed errors if they're not defined or bogus dependencies.

So when scanning, we should ignore explicitly defined relative 'from' imports (they look like "from . sibling import foo" or "from .. uncle import bar").

Branch coming.

[Martin Pitt (pitti)]

Committed to trunk, thanks!

[Martin Pitt (pitti)]

Note that in the followup commit I rewrote the function to actually catch all relative imports (case 2 in the merge proposal). That allowed me to revert the node.level workaround again.

[Michael Terry (mterry)]

Ah, bummer, this never made it into natty. I really kind of needed it to, as it causes bad user experience in quickly.

I'll craft an SRU for it.

[Martin Pitt (pitti)]

Accepted python-distutils-extra into natty-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

[Martin Pitt (pitti)]

I uploaded 2.27-1 to Debian unstable, which fixes this. We'll get it into oneiric in the next days through auto-syncs.

[Launchpad Janitor (janitor)]

This bug was fixed in the package python-distutils-extra - 2.27-1

---------------
python-distutils-extra (2.27-1) unstable; urgency=low

  * auto.py: Cleaner approach to determine whether a module is locally
    provided. This now catches all relative imports. (LP: #746565)
  * Fix installation of symlinks in data/ dir (LP: #770566):
    - test/auto.py: Add test for installing a symlink which points to a
      nonexisting target directory/file. This reproduces the gist of the
      problem.
    - test/auto.py: Preserve symlinks in copytree() calls, so that we can
      actually verify that symlinks are preserved properly.
    - test/auto.py: Drop requirement that diff throws no error messages, as it
      will complain about the broken symlink.
    - DistUtilsExtra/auto.py, install_auto: Use os.walk() instead of
      distutils.filelist.findall() to pick out symlinks, as the latter fails
      badly with broken symlinks.
    - DistUtilsExtra/command/build_icons.py: Ignore symbolic links. distutils
      breaks on them when they point to a nonexisting target, and we handle
      them in auto.py.
  * DistUtilsExtra/auto.py: Put back "except .. as" syntax, now that we
    dropped Python 2.5. Drop 2to3 from debian/rules for good now.
  * debian/control: Bump minimal Python version to >= 2.6.
 -- Ubuntu Archive Auto-Sync <email address hidden> Sun, 22 May 2011 13:55:08 +0000

[Michael Terry (mterry)]

This is another call for any interested parties to test and verify the fix in natty-proposed.

[marmuta (marmuta)]

Revision 248 breaks the package build for Onboard in Oneiric and according to Francesco Fumanti also in Natty.

setup.py: error: no such option: --build-base

The reason is apparently, that importing certain files triggers Onboards own command line processing, which obviously doesn't know or care about setup.py options.
I could work around this, but I wonder if it is safe to assume for DistUtilsExtra that importing files out of context doesn't have any adverse side effects.

[Martin Pitt (pitti)]

Marking as v-failed for now to prevent this from going into -updates. I'll investigate this more closely tomorrow.

[Martin Pitt (pitti)]

I confirmed the regression in onboard, and I also just happened to stumble over it in xdiagnose (where a module import throws an exception). I now added test cases for both variants (onboard and xdiagnose), and committed a fix:

  http://bazaar.launchpad.net/~python-distutils-extra-hackers/python-distutils-extra/debian/revision/256

I'll upload 2.28 now.

[Michael Terry (mterry)]

I've uploaded a new natty-proposed version with your latest upstream changes mentioned in comment #11. I'd really like to see this land in natty.

[Chris Halse Rogers (raof)]

Hello Michael, or anyone else affected,

Accepted python-distutils-extra into natty-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

[Paolo Sammicheli (xdatap1)]

Hello,

I just checked the 2.26-2ubuntu0.2 version available in proposed and it solve the problem.

Thanks!

[Launchpad Janitor (janitor)]

This bug was fixed in the package python-distutils-extra - 2.26-2ubuntu0.2

---------------
python-distutils-extra (2.26-2ubuntu0.2) natty-proposed; urgency=low

  * debian/patches/ignore-relative-imports.patch:
    - Update with a further fix from trunk to fix a couple regressions

python-distutils-extra (2.26-2ubuntu0.1) natty-proposed; urgency=low

  * debian/patches/ignore-relative-imports.patch:
    - Backport from trunk to ignore relative imports in source packages.
      This prevents Quickly from treating its own relative imports as
      errors. LP: #746565
 -- Michael Terry <email address hidden> Thu, 18 Aug 2011 14:27:05 -0400