Possible MBF for SyntaxWarning with Python 3.8

[Stuart Prescott <stuart@debian.org>]

Hi all,

Python 3.8 generates a SyntaxWarning when it sees code that is most probably 
incorrect such as

	if foo is 0:
	 ...

	if bar is not 'quux':
	 ...

	if baz is ():
	 ...

When the Debian package is installed, py3compile sees such code and causes a 
pile of SyntaxWarning messages to be spewed in the middle of the apt run. 
Since code like the above is wrong and errors are unwelcome for the user (and 
are likely to generate quite a lot of support requests), I propose an MBF on 
the issue.

Looking through piuparts installation logs for packages in sid, I've so far 
identified 75 binary packages that emit SyntaxWarning on installation, but that 
is only the subset of python packages that happen to have been installed by 
piuparts over the last 60 days. I guess we'll need to continue to look at 
piuparts logs and that we will find more.

Any thoughts?

cheers
Stuart



raw entries from piuparts logs: https://people.debian.org/~stuart/swlog

data for bug reports: https://people.debian.org/~stuart/swbugs

ddlist: https://people.debian.org/~stuart/swddlist

bug template:

Subject: {package} generates SyntaxWarning at install time

Package: {package}
Version: {version}
Severity: important
Tags: sid bullseye
User: debian-python@lists.debian.org
Usertags: py38syntaxwarning

Dear maintainer,

Python 3.8 introduced a series of checks that look for code that is highly
likely to be buggy. When the code is processed by Python 3.8, it emits a
SyntaxWarning complaining about the code. For Debian packages, these
warnings will be visible at package install time.

This package generates SyntaxWarning output during package install:

{output}

Fixing this class of bug is generally straightforward and the upstream
developers may have already done so.

If there are questions, please ask for help on IRC #debian-python, or
the debian-python@lists.debian.org mailing list.




-- 
Stuart Prescott    http://www.nanonanonano.net/   stuart@nanonanonano.net
Debian Developer   http://www.debian.org/         stuart@debian.org
GPG fingerprint    90E2 D2C1 AD14 6A1B 7EBB 891D BBC1 7EBB 1396 F2F7