Zero byte successful merge after error from dpkg-mergechangelogs

[Marcin Juszkiewicz]

I was merging lp:ubuntu/gcc-4.6 into my lp:~hrw/ubuntu/precise/gcc-4.6/cross-fixes branch and as result I got debian/changelog dropped to 0 size:

09:29 hrw@puchatek:gcc-4.6-my-cross-fixes$ bzr merge lp:ubuntu/gcc-4.6
Most recent Ubuntu version: 4.6.2-5ubuntu1
Packaging branch status: CURRENT
Traceback (most recent call last):e merge 1/16
  File "/usr/lib/python2.7/logging/__init__.py", line 865, in emit
    stream.write(fs % msg.encode("UTF-8"))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc5 in position 23: ordinal not in range(128)
Logged from file merge_changelog.py, line 73
+N debian/patches/gcc-multilib64-multiarch-trunk.diff
+N debian/patches/gcc-powerpc-nof-trunk.diff
+N debian/patches/libffi-powerpc-sysv-without-string-ops.diff
 M debian/changelog
 M debian/control
 M debian/control.m4
-D debian/patches/arm-unbreak-eabi-armv4t.diff
 M debian/patches/armhf-triplet-trunk.diff
 M debian/patches/gcc-multiarch.diff
 M debian/patches/svn-updates-linaro.diff
 M debian/patches/svn-updates.diff
 M debian/rules.conf
 M debian/rules.defs
 M debian/rules.parameters
 M debian/rules.patch
 M debian/rules2
Text conflict in debian/control.m4
Text conflict in debian/rules2
2 conflicts encountered.

09:54 hrw@puchatek:debian$ bzr diff|diffstat
 changelog |10138 --------------------

According to mgz from #bzr bug is in a way how bzr-builddeb/merge_changelog.py uses logger. After changing code I got:

10:08 hrw@puchatek:debian$ LC_ALL=C bzr remerge changelog
debian/changelog is not conflicted
dpkg-mergechangelogs: warning: /tmp/tmpiGP5_Sdeb_changelog_merge/changelog.this(l0): found eof where expected first heading
dpkg-mergechangelogs: error: ss-970814-1 is not a valid version

All changes applied successfully.

And changelog file was still empty.

Change was in/usr/share/pyshared/bzrlib/plugins/builddeb/merge_changelog.py file (line 73):

- _logger.warning('%s', stderr)
+ _logger.warning('%s', stderr.decode("utf-8", "replace"))

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: bzr-builddeb 2.7.9ubuntu1
ProcVersionSignature: Ubuntu 3.1.0-2.3-generic 3.1.0
Uname: Linux 3.1.0-2-generic x86_64
ApportVersion: 1.26-0ubuntu1
Architecture: amd64
Date: Tue Nov 22 09:52:45 2011
InstallationMedia: Kubuntu 10.04 "Lucid Lynx" - Release Candidate amd64 (20100419.1)
PackageArchitecture: all
SourcePackage: bzr-builddeb
UpgradeStatus: No upgrade log present (probably fresh install)

[Marcin Juszkiewicz (hrw)]

Bug happened because of Polish error message was UTF-8:

debian/changelog is not conflicted
dpkg-mergechangelogs: ostrzeżenie: /tmp/tmpKJKi6cdeb_changelog_merge/changelog.this(l0): oczekiwano first heading, a znaleziono koniec pliku
dpkg-mergechangelogs: błąd: ss-970814-1 is not a valid version

All changes applied successfully.

[Marcin Juszkiewicz (hrw)]

lp:~hrw/ubuntu/precise/gcc-4.6/cross-fixes branch was at r71 before merge

[Martin Packman (gz)]

Okay, I think the logging issue is best handled upstream in bzrlib, see bug 714449 for that.

What I understand about the underlying problem from builddeb.merge_changelog from the output is:

* Running `bzr --no-plugins remerge debian/changelog` avoids the issue by disabling the changelog merge hook

* Despite stderr output, the merge hook returns "successful" but produces an empty debian/changelog

* The meaning of the errors is:

    dpkg-mergechangelogs: warning: /tmp/tmpiGP5_Sdeb_changelog_merge/changelog.this(l0): found eof where expected first heading

^ The hook is creating an empty changelog.this

    dpkg-mergechangelogs: error: ss-970814-1 is not a valid version

^ An early entry in the changelog has a bad version:

    egcs (ss-970814-1) experimental; urgency=low

      * Initial packaging (of initial snapshot!)

     -- Galen Hazelwood <email address hidden> Wed, 20 Aug 1997 00:36:28 +0000

* Merging the attached files here with dpkg-mergechangelogs works, without "not a valid version" appearing

* Merging the attached files with an empty changelog.this results in *some* output

Trying the same merge locally to work out where the hook is going wrong seems like a good next step, though some of this code has changed in more recent bzr-builddeb versions.

[Rick Spencer (rick-rickspencer3)]

Seems the bug is confirmed, so setting it as such. Chose an importance of Medium.

[Martin Packman (gz)]

So, the problem is that newer versions of dpkg-mergechangelogs abort given a the 'ss-970814-1' package version, and builddeb doesn't correctly detect that case. Have sent a patch upstream to dpkg, and have a branch fixing both the log encoding handling and this error case for builddeb.

[Launchpad Janitor (janitor)]

This bug was fixed in the package bzr-builddeb - 2.8.0

---------------
bzr-builddeb (2.8.0) unstable; urgency=low

  [ Jonathan Riddell ]
  * Add get-orig-source command which will get the upstream tar file.
    LP: #862188
  * Change "bd-do" command to "builddeb-do" and alias "bd-do".
  * Add commit-message-from-changelog option for those who do not
    want commit message set automatically

  [ Jelmer Vernooij ]
  * Support importing and building packages with multiple upstream
    tarballs. LP: #653757, LP: #664834
  * Move .bzr-builddeb/default.conf to debian/bzr-builddeb.conf.
    LP: #793137
  * Fix test suite on Lucid, where dpkg-mergechangelogs is not available.

  [ Martin Packman ]
  * Fix test_utf8_changelog when run with older versions of python-debian.

  [ Jelmer Vernooij ]
  * Support svn-buildpackage tag names to find upstream versions.
    LP: #874263
  * Support --revision argument to merge-package. LP: #888590
  * By default, don't override the commit message from debian/changelog
    unless 'commit-message-from-changelog' is explicitly set to True. LP: #812749
  * Support running dep3-patch against remote repositories, and with
    open-ended revision ranges. LP: #893608
  * Fix finding orig tarballs in directories also containing filenames
    with non-utf8 characters. LP: #865753
  * bzr-builddeb now prefers the 'get-packaged-orig-source' rule to
    retrieve the packaged upstream source, and warns about
    'get-orig-source'. LP: #409862
  * Support translations.

  [ Martin Packman ]
  * Deal with invalid versions and bad encoding in the changelog merge
    hook. LP: #893495

 -- Jelmer Vernooij <email address hidden> Fri, 16 Dec 2011 19:58:57 +0100