Richard Fearn (richardfearn(a)gmail.com) said:
> On 28 December 2013 16:43, Bruno Wolff III <bruno(a)wolff.to> wrote:
>>
https://fedoraproject.org/wiki/Packaging:Guidelines#The_.25pretrans_scrip...
>> Notes that you need to use lua in pretrans scriptlets, not shell commands.
>
> Thanks. I've already seen that. It doesn't seem to make any difference
> whether it's a bash scriptlet or a lua scriptlet, though; irrespective
> of what language is used to delete the symlink, the problem still
> occurs.
>
>> I haven't found an example for you to copy, but note there are still some
>> cases where changing symlinks to directories or vise versa won't work with
>> rpm (
https://bugzilla.redhat.com/show_bug.cgi?id=975909).
>
> I think deleting the symlink manually may be revealing a problem in
> rpm. It seems to treat /usr/share/javadoc/test-1/
> hello (from the old
> package) and /usr/share/javadoc/test/hello (from the new package) as
> the same thing. Since the new package is installing
> /usr/share/javadoc/test/hello, it therefore decides to 'skip' the old
> 'hello' file, rather than 'erase' it.
>
> I'm not sure yet why these two paths are considered to be the same...
I believe (but can't confirm ATM) that file disposition checks (i.e., which
files are added/removed/replaced) happen before pretrans scripts. So if
you're using pretrans scripts to change paths that were valid
pre-transaction to something else, weird results may happen.
%pretrans runs before the file disposition checks precisely to allow
these kinds of hacks to work ... and that's also the very reason it's so
problematic in many ways.
I saw this thread during the x-mas period but apparently forgot to
reply: Richards reproducer appears to point out a regression (in rpm >=
4.11, or perhaps surface a long-dormant bug in a piece of
symlink-checking code which was previously broken. Or then its been
there all along but never reported with an actual reproducer. Not sure
which one yet...
- Panu -