qbrz appears to depend on sip version 4

[Olaf Seibert]

I'm packaging qbrz for pkgsrc, and when refreshing all my packages, I noticed that "brz qlog" only worked if I also installed the package "py39-sip-4.19.25". Otherwise there would be an error

$ brz qlog
Unable to load plugin 'qbrz' from '/usr/pkg/lib/python3.9/site-packages/breezy/plugins/qbrz': No module named 'sip'
brz: ERROR: unknown command "qlog". Perhaps you meant "log"

This is likely because .../site-packages/breezy/plugins/qbrz/__init__.py contains

# TODO: this might not be necessary now
# RJL to speed development, retain Qt4 for now: use ``sip.setapi`` to request
# version 1 behaviour for ``QVariant`` (otherwise it's not available for python3)
import sip
sip.setapi('QVariant', 2)

However, sip versions newer than 4 don't have a 'sip' module; instead they have a 'sipbuild' module. If I understand those different versions correctly.

On the other hand, py-Qt5 uses sip version 6 (but maybe doesn't need it at runtime? I'm not sure).

Requiring 2 sip versions isn't very nice; version 4 is quite old and seems to be deprecated; also I suspect it's not needed anyway since the comment above refers to Qt4, which is no longer used.

[Olaf Seibert (rhialto)]

If I look at the packaging of PyQt5_sip-12.11.0.tar.gz (used py py-Qt5), there is a

${PYSITELIB}/PyQt5/sip.so

so maybe that's the one that's wanted by qbrz; but it would need to be imported as PyQt5.sip instead, I expect.

[Robert Ladyman (saccadic-masking)]

I checked the PyQt5 documentation and the import sip will fail if no PyQt5 imports are performed before it.

https://www.riverbankcomputing.com/static/Docs/PyQt5/incompatibilities.html#pyqt-v5-11

Have adjusted imports accordingly. Just running tests to see if removing the setapi() call is OK (I note that setapi() has been deprecated).

[Luke Howison (lukehnz)]

I'm getting this error when installing qbzr:

ERROR: Could not find a version that satisfies the requirement python3-sip (from qbrz) (from versions: none)
ERROR: No matching distribution found for python3-sip

I have installed python3-sip (4.19.25+dfsg-3build1). This is on Ubuntu 22.04.3 LTS

[Robert Ladyman (saccadic-masking)]

Luke, many thanks for the report. Did you install qbzr from Ubuntu itself or download and attempt to install qbrz from code?

[Luke Howison (lukehnz)]

Hi Robert, I was following the instructions on Launchpad (bzr branch lp:qbrz / make tarball), I didn't realise I could just do 'sudo apt install qbrz'. That worked great, thanks.

I did encounter several bugs which cause qbrz to crash, but I'll report those separately.

[Robert Ladyman (saccadic-masking)]

Thanks Luke - all bugs appreciated.