package doc-base 0.10.7 failed to install/upgrade: installed doc-base package post-installation script subprocess returned error exit status 10

[Jordan]

I received this error while doing a do-release-upgrade from Ubuntu 16.04 to Ubuntu 18.04.

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: doc-base 0.10.7
ProcVersionSignature: Ubuntu 4.4.0-176.206-generic 4.4.211
Uname: Linux 4.4.0-176-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.20.1-0ubuntu2.22
Architecture: amd64
Date: Fri Mar 27 11:12:04 2020
ErrorMessage: installed doc-base package post-installation script subprocess returned error exit status 10
InstallationDate: Installed on 2015-12-16 (1563 days ago)
InstallationMedia: Ubuntu-GNOME 15.10 "Wily Werewolf" - Release amd64 (20151021)
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2.3
 apt 1.2.32
SourcePackage: doc-base
Title: package doc-base 0.10.7 failed to install/upgrade: installed doc-base package post-installation script subprocess returned error exit status 10
UpgradeStatus: Upgraded to bionic on 2020-03-27 (0 days ago)

[Jordan (jordanu)]

I think that the problem somehow involves perl being upgraded from 5.22.1 to 5.26 but 5.22.1 still being used when the trigger for doc-base is invoked.

From the dpkg terminal log:

<snip>

Preparing to unpack .../perl_5.26.1-6ubuntu0.3_amd64.deb ...
Unpacking perl (5.26.1-6ubuntu0.3) over (5.22.1-9ubuntu0.6) ...
Selecting previously unselected package perl-modules-5.26.
Preparing to unpack .../perl-modules-5.26_5.26.1-6ubuntu0.3_all.deb ...
Unpacking perl-modules-5.26 (5.26.1-6ubuntu0.3) ...

<snip>

Processing triggers for doc-base (0.10.7) ...
Database error: Cannot read file `/var/lib/doc-base/info/status.yml': Can't locate PerlIO.pm in @INC (you may need to install the PerlIO module) (@INC contains: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.22.1 /usr/local/share/perl/5.22.1 /usr/lib/x86_64-linux-gnu/perl5/5.22 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.22 /usr/share/perl/5.22 /usr/local/lib/site_perl /usr/lib/x86_64-linux-gnu/perl-base .) at /usr/share/perl5/YAML/Tiny.pm line 183.
BEGIN failed--compilation aborted.

<snip>

Note that despite the fact that perl 5.22.1 has been replaced with perl 5.26, @INC still contains /usr/share/perl/5.22.1/ .

I have made a pre-upgrade btrfs snapshot. I plan to revert to it then uninstall doc-base and re-run the upgrade, then re-install doc-base. I plan to keep the snapshot if any developer would like me to test upgrade again with a fixed package.