Re: On robustness of maintainer scripts

[Jakub Wilk <jwilk@debian.org>]

* Piotr Ożarowski <piotr@debian.org>, 2013-05-11, 00:29:
> > postinst
> > ========
> [...]
> > Proposed solution:
> > 1) Wait until #671711 is fixed.
> > 3) Make pycompile a shell script that does only two simple things:
> > - write options it was called with to a file, say, 
> > /var/lib/python/pyX.Ycompile.todo;
> > - use dpkg-trigger to trigger pythonX.Y.
>
> why not generate maintainer scripts without pycompile at all?

- There are hundreds of packages that use py{compile,clean} in the 
maintainer script. The script needs to continue to exist at least until 
jessie is released.
- Fixing the problem in py{compile,clean} means that even the packages 
that haven't been rebuilt can benefit from the fix.
- If you take all corner cases into cosideration, the required gets 
pretty complicated. IMO too complicated to risk putting the code 
directly into maintainer scripts.

> I wanted to delegate as much as possible to interpreter packages, but
> your idea with temp. files is even better - maintainer scripts can
> look like this:
>
> | touch /usr/lib/pythonX.Y/dist-packages/namespace/__init__.py¹
> | touch /usr/lib/pythonX.Z/dist-packages/namespace/__init__.py¹
>
> | dpkg -L <package> | grep \.py$ | while read file
> | do
> | 	echo "${file}" >> /var/lib/python/pyX.Ycompile.todo
> | 	echo "${file}" >> /var/lib/python/pyX.Zcompile.todo
> | done

Here you need to check with versions are supported, and which of them 
are installed^Wunpacked.

Oh, and the call to dpkg-trigger is missing. /o\

> [¹] namespace has to be created here as other packages might want to 
> use given library in maintainer scipts, even without .pyc files

ACK

> ("test -f ... ||" is probably missing here)

Yes, it is missing. :)

> > prerm
> > =====
> [...]
> > Proposed solution:
> > Get rid of /usr/bin/pyclean, so that the fallback code is activated. 
> > \o/ Just kidding. :) Not only that would almost certainly have 
> > unintended consequences, but also the fallback code doesn't look 
> > complete: it doesn't take care of namespaces.
> >
> > Actual proposed solution:
> > Rewrite /usr/bin/pyclean in shell.
>
> again, removing /usr/bin/pyclean is not that bad idea. I like it and 
> will try to provide example scripts for interpreter packages (and then 
> generate prerm like in postinst example)

You need to remove namespaces, remove files from *.todo...
I wouldn't dare to put it directly to prerm.

--
Jakub Wilk