Comment 0 for bug 1875741

Upgrading my MAAS server from Bionic / 2.6 to Focal / 2.7. The upgrade broke during handling of MAAS with a traceback. (Apologies for the formatting, this was copied from console and the formatting got skewed there for some reason).

Preparing to unpack .../6-libkrb5support0_1.17-6ubuntu4_amd64.deb ...
Unpacking libkrb5support0:amd64 (1.17-6ubuntu4) over (1.16-2ubuntu0.1) ...
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/apt/cache.py", line 289, in __getitem__
     return self._weakref[key]
File "/usr/lib/python3.6/weakref.py", line 137, in __getitem__
     o = self.data[key]()
     KeyError: '2-maas'

During handling of the above exception, another exception occurred:
                                                                                                       Traceback (most recent call last):
                                                                                                                                           File "/usr/lib/python3/dist-packages/apt/cache.py", line 292, in __getitem__
     rawpkg = self._cache[key]
     KeyError: '2-maas'

During handling of the above exception, another exception occurred:
                                                                                                                 Traceback (most recent call last):
                                                                                                                                                          File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 126, in _apt_pkg
     return self._cache()[package]
File "/usr/lib/python3/dist-packages/apt/cache.py", line 294, in __getitem__
     raise KeyError('The cache has no package named %r' % key)
                                                                                                                                                                                                        KeyError: "The cache has no package named '2-maas'"

During handling of the above exception, another exception occurred:
                                                                                                           Traceback (most recent call last):
                                                                                                                                               File "/usr/share/apport/package_hook", line 48, in <module>
pr['SourcePackage'] = apport.packaging.get_source(options.package)
File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 159, in get_source
     if self._apt_pkg(package).installed:
File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 128, in _apt_pkg
     raise ValueError('package %s does not exist' % package)
     ValueError: package 2-maas does not exist
                                                                                                                                                                      Preparing to unpack .../7-libcom-err2_1.45.5-2ubuntu1_amd64.deb ...
Unpacking libcom-err2:amd64 (1.45.5-2ubuntu1) over (1.44.1-1ubuntu1.3) ...
Errors were encountered while processing:
 /tmp/apt-dpkg-install-xFEKoD/2-maas_1%3a0.6_all.deb
Exception during pm.DoInstall(): E:Sub-process /usr/bin/dpkg returned an error code (1)

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ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: maas 2.6.2-7841-ga10625be3-0ubuntu1~18.04.1
ProcVersionSignature: Ubuntu 4.15.0-65.74-generic 4.15.18
Uname: Linux 4.15.0-65-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.14
Architecture: amd64
Date: Tue Apr 28 19:59:25 2020
ErrorMessage: new maas package pre-installation script subprocess returned error exit status 1
PackageArchitecture: all
Python3Details: /usr/bin/python3.6, Python 3.6.9, python3-minimal, 3.6.7-1~18.04
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2.3
 apt 1.6.12
SourcePackage: maas
Title: package maas 2.6.2-7841-ga10625be3-0ubuntu1~18.04.1 failed to install/upgrade: new maas package pre-installation script subprocess returned error exit status 1
UpgradeStatus: Upgraded to focal on 2020-04-28 (0 days ago)