Improve epub compatibility

10 jobs for master in 9 minutes and 20 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Linting
passed #185309
linting:bandit

00:00:12

passed #185312
linting:codespell

00:00:11

passed #185322
linting:mypy

00:00:12

passed #185319
linting:pyflakes

00:00:11

passed #185316
linting:pylint

00:00:22

 
  Test
passed #185325
tests:archlinux

00:01:05

passed #185330
tests:debian

00:01:04

failed #185333
tests:debian_with_bubblewrap

00:00:31

passed #185334
tests:fedora

00:05:32

passed #185337
tests:gentoo

00:08:02

 
Name Stage Failure
failed
tests:debian_with_bubblewrap Test

----------------------------------------------------------------------
Ran 119 tests in 20.180s

FAILED (failures=6, errors=36)
[+] Testing pdf
[+] Testing png
Cleaning up file based variables
ERROR: Job failed: exit code 1