post-install script fails with (apparent) python2 error

[Jeff Abrahamson]

Setting up bookworm (1.1.2+git20200823-1) ...
  File "/usr/share/com.github.babluboy.bookworm/scripts/mobi_lib/mobiml2xhtml.py", line 249
    print " - fixed by injecting empty start tag ", tname
          ^
SyntaxError: Missing parentheses in call to 'print'. Did you mean print(" - fixed by injecting empty start tag ", tname)?

dpkg: error processing package bookworm (--configure):
 installed bookworm package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
 bookworm
E: Sub-process /usr/bin/dpkg returned an error code (1)

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: bookworm 1.1.2+git20200823-1
ProcVersionSignature: Ubuntu 5.11.0-49.55-generic 5.11.22
Uname: Linux 5.11.0-49-generic x86_64
ApportVersion: 2.20.11-0ubuntu65.4
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: i3
Date: Fri Jul 15 14:56:08 2022
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-10-23 (2456 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
SourcePackage: bookworm
UpgradeStatus: Upgraded to hirsute on 2022-04-01 (104 days ago)

[Aaron Rainbolt (arraybolt3)]

Thank you for reporting this bug to Ubuntu.

Ubuntu 21.04 (hirsute) reached end-of-life on January 20, 2022.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

I would highly recommend that you back up your system and upgrade to the newest LTS release, 22.04, and then try again. In the event the upgrade fails, you may have to reinstall the system from scratch and restore your files. Make sure you have an Ubuntu 22.04 live USB available for in the event that happens.