package python3-breezy 3.2.1+bzr7585-1build1 failed to install/upgrade: installed python3-breezy package post-installation script subprocess returned error exit status 1

[Romain Couturat]

during hirsute to jammy upgrade

ProblemType: Package
DistroRelease: Ubuntu 22.04
Package: python3-breezy 3.2.1+bzr7585-1build1
ProcVersionSignature: Ubuntu 5.13.0-40.45-generic 5.13.19
Uname: Linux 5.13.0-40-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu82
Architecture: amd64
CasperMD5CheckResult: pass
Date: Thu Apr 21 23:10:18 2022
DuplicateSignature:
 package:python3-breezy:3.2.1+bzr7585-1build1
 Setting up python3-breezy (3.2.1+bzr7585-1build1) ...
 [Errno 2] No such file or directory: '/usr/lib/python3/dist-packages/breezy/git/__init__.py'dpkg: error processing package python3-breezy (--configure):
  installed python3-breezy package post-installation script subprocess returned error exit status 1
ErrorMessage: installed python3-breezy package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2021-06-09 (316 days ago)
InstallationMedia: Ubuntu 21.04 "Hirsute Hippo" - Release amd64 (20210420)
Python3Details: /usr/bin/python3.10, Python 3.10.4, python3-minimal, 3.10.4-0ubuntu2
PythonDetails: /usr/bin/python3.10, Python 3.10.4, python-is-python3, 3.9.2-2
RebootRequiredPkgs: Error: path contained symlinks.
RelatedPackageVersions:
 dpkg 1.21.1ubuntu2
 apt 2.4.5
SourcePackage: grub2
Title: package python3-breezy 3.2.1+bzr7585-1build1 failed to install/upgrade: installed python3-breezy package post-installation script subprocess returned error exit status 1
UpgradeStatus: Upgraded to jammy on 2022-04-21 (0 days ago)

[Romain Couturat (romaincout)]

/usr/lib/python3/dist-packages/breezy/git/__init__.py
was getting installed as
/usr/lib/python3/dist-packages/breezy/git/__init__.py.distrib
and apt failing on postinst step

I fixed it locally by skipping postinstall
(see https://askubuntu.com/questions/482928/ignore-apt-get-postinstall-scripts-automatically )
copying the file from the package
cp usr/lib/python3/dist-packages/breezy/git/__init__.py /usr/lib/python3/dist-packages/breezy/git/__init__.py
and running applicable postinstall step manually :
py3compile -p python3-breezy:amd64

Turns out I had dpkg-divert that file, I removed the divert with
dpkg-divert --no-rename --remove /usr/lib/python3/dist-packages/breezy/git/__init__.py
and now
apt install --reinstall python3-breezy
works as expected