Please see exchange from ubuntu-devel mailing list:

Date: Wed, 14 Oct 2020 09:06:35 +0900
From: Norbert Preining <email address hidden>
To: <email address hidden>
Cc: Eli Schwartz <email address hidden>
Subject: Ubuntu Focal update of broken Calibre package
Message-ID: <email address hidden>
Content-Type: text/plain; charset=us-ascii

Dear all,

(please Cc)

I am the Debian maintainer of Calibre, and unfortunately it seems that
for Focal Ubuntu has pulled a preliminary version of Calibre, which is
**seriously** broken and unusable, not even starting in most cases.

We were forced by the Python3 transition to temporarily ship pre-release
versions of Calibre. In particular, Ubuntu Focal ships
	4.99.4+dfsg+really4.12.0-1build1
which is version 4.12 with experimental Python3 patches on top of it.
This worked for a short time being until Calibre 5 was released with
proper Python3 support.

Due to this unfortunate squeeze in release timing, Ubuntu Focal users
now have a seriously broken Calibre, and upstream is swamped with bug
reports.

I would strongly suggest and support, and help preparing, an update to
Focal based on the current version in Debian/testing, 5.2.0+dfsg-1,
which has been out since quite some time and field-tested with Python3
in various environments, due to upstream having switched to Py3, too.

Is the above (update to 5.2.0) possible in Ubuntu Focal, and if yes,
what kind if steps are necessary?

Note that I am not an Ubuntu developers, but Debian developer and
maintainer of Calibre.

Thanks and all the best

Norbert

Date: Wed, 14 Oct 2020 12:45:40 +0200
From: Lukasz Zemczak <email address hidden>
To: Norbert Preining <email address hidden>
Cc: ubuntu-devel <email address hidden>, Eli Schwartz
	<email address hidden>
Subject: Re: Ubuntu Focal update of broken Calibre package
Message-ID:
	<email address hidden>
Content-Type: text/plain; charset="UTF-8"

Hello Norbert,

With my SRU team hat on, after reading what you said about the status
of current calibre, I would say it is possible to update the package
version in focal to 5.2.0. But we would need to know a bit more, and
there is some (important) paperwork to do.

First thing to remember is that for a new version to be releasable to
a stable series it also has to be present in all the newer series as
well - so groovy upwards. We are long past debian import freeze so
groovy is still on 4.99.12+dfsg+really4.23.0-1 - and syncing 5.2.0
now, so late in the cycle, requires an approved Feature Freeze
Exception [1], since we're also past feature freeze. It's a very very
unfortunate time, since Final Freeze for groovy is tomorrow, and we're
a bit reluctant with accepting risky pieces. The 'good' news is,
calibre is only seeded in our Ubuntu Studio flavor, so the impact
should be manageable. I would like the Ubuntu Studio flavor
representatives to chip in and (maybe) help out with the paperwork
there.

Once we have it in groovy+ we can look into backporting it to focal.
This requires filling in some SRU paperwork as per the policy [2].
What makes it a bit problematic from the SRU perspective is that the
debdiff between 4.99.4+dfsg+really4.12.0-1build1 (in focal) and 5.2.0
is 7600433 lines long. Looking at the diff itself, most of it are
translation changes, but still... it's quite a change nevertheless.
The things that need to be thought of before performing the backport:
 * How badly is calibre broken on focal right now? Is it really
unusable in its current state? Examples of how broken things are so
that we can understand the situation better
 * How does the automated test coverage on calibre look like? Do all
new features come with unit testing? What about autopkgtests (I don't
think I see any?)?
 * What would be the acceptance criteria for the new version? What
testing should be performed to make sure the new version works as
expected and doesn't regress any existing users (assuming calibre in
focal right now is at least usable to some extent)

If needed, we can help a bit with some of the SRU bits.

Cheers,

Hi Norbert, Lukasz and all!

On Wed, Oct 14, 2020 at 09:06:35AM +0900, Norbert Preining wrote:
> Dear all,
>
> (please Cc)
>
> I am the Debian maintainer of Calibre, and unfortunately it seems that
> for Focal Ubuntu has pulled a preliminary version of Calibre, which is
> **seriously** broken and unusable, not even starting in most cases.
>
> We were forced by the Python3 transition to temporarily ship pre-release
> versions of Calibre. In particular, Ubuntu Focal ships
> 	4.99.4+dfsg+really4.12.0-1build1
> which is version 4.12 with experimental Python3 patches on top of it.
> This worked for a short time being until Calibre 5 was released with
> proper Python3 support.
>
> Due to this unfortunate squeeze in release timing, Ubuntu Focal users
> now have a seriously broken Calibre, and upstream is swamped with bug
> reports.
>
> I would strongly suggest and support, and help preparing, an update to
> Focal based on the current version in Debian/testing, 5.2.0+dfsg-1,
> which has been out since quite some time and field-tested with Python3
> in various environments, due to upstream having switched to Py3, too.

Unfortunately, Calibre 5.x requires SIP 5 and PyQt5 that is built against
SIP 5. Moving PyQt5 to the new SIP is a major transition, that happened
in Debian recently (two weeks ago) and did not happen in Ubuntu yet because
of freeze.

This requires changes in many packages simultaneously: at least pyqt5,
pyqt5charts, pyqt5webengine, qscintilla2, calibre, python-poppler-qt5,
veusz, krita and qgis.

I am planning to land this change early in Groovy+1 cycle.

> Is the above (update to 5.2.0) possible in Ubuntu Focal, and if yes,
> what kind if steps are necessary?

So for Focal and Groovy we need a version of Calibre that still uses SIP 4.
Last such version in Debian was 4.99.12+dfsg+really4.23.0-1, Groovy already
has that. If you know some specific fixes, maybe they can be applied on top
of what Focal or Groovy has.

--
Dmitry Shachnev