Ubuntu Focal update of broken Calibre package

James Cuzella james.cuzella at lyraphase.com
Wed Dec 23 01:11:15 UTC 2020

Thanks Dmitry for pointing me in the right direction!

I tried to backport the set of Qt5 and qtwebengine packages and found out
what large set of build dependencies it was!

So what I said is true: this requires simultaneous changes in many packages,
> even if it's just a rebuild for some of them.
Yes!  Qt5 is indeed a very large project too!  I'm sure there is a Lord of
the Rings meme that applies here like: "One does not simply backport Qt5" 😄

Simply using the backportpackage tool on qtwebengine-opensource-src started
a build dependency hunt that resulted in finding a massive set of Qt5
packages that needed to be backported (without relaxing version
A lot of these eventually resolved into being blocked on circular
dependency chains.

I was able to spend a few hours on this to visually represent what I found
(See Gist linked below):


I'm not sure how the Debian or Ubuntu teams build and backport Qt5 packages
when so many build dependencies resolve circularly.
I suppose they must bootstrap this dependency chain somehow, but it seems
like more work than I have time to figure out at the moment.

Any ideas for how to simplify this?

- James Cuzella

On Sun, Dec 13, 2020 at 10:16 AM Dmitry Shachnev <mitya57 at ubuntu.com> wrote:

> Hi James!
> On Fri, Dec 11, 2020 at 08:43:16PM -0700, James Cuzella wrote:
> > I would appreciate any help with figuring out how to get that
> > last python3-pyqt5.qtwebengine package to be generated from the pyqt5
> > source package.  I'm assuming this is where it comes from, given that all
> > the other similarly named ones were generated from that one.  Also, the
> > Debian package site shows this as the source package:
> > https://packages.debian.org/stretch/python3-pyqt5.qtwebengine
> It used to be built from pyqt5 source, but since then it got a new source
> package, pyqt5webengine:
> https://launchpad.net/ubuntu/+source/pyqt5webengine
> https://packages.debian.org/sid/source/pyqt5webengine
> --
> Dmitry Shachnev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.ubuntu.com/archives/ubuntu-devel/attachments/20201222/e9c1787f/attachment.html>

More information about the ubuntu-devel mailing list