Another great update

[Kalev Lember]

On 03/07/2010 12:52 AM, Orcan Ogetbil wrote:
> Yet moreover you also have the option of updating bugfixes in
> addition, leaving the enhancement updates out.

I really don't think I have that option. It might work in some cases,
but generally it's bound to fail.

A security update in an application which uses KDE or Qt libs (both of
which were upgraded to a new feature release recently in F-11 and F-12)
will be built against those new libs. It's a common practice that new
versions of libraries continue working with programs that were compiled
against an older version of said library. But it doesn't work the other
way around: something built against Qt 4.5 is supposed to continue
working with Qt 4.6, but an application built against Qt 4.6 will have
no guarantees that it also runs with Qt 4.5. This is the reason why only
applying security updates doesn't work if underlying libraries get
upgraded to new feature releases meanwhile.


Let me quote mail titled "Read this if your package BuildRequires
qt(4)-devel!!!" here.

On 02/22/2010 05:40 AM, Kevin Kofler wrote:
> for all maintainers of packages which BuildRequire qt4-devel (or qt-devel, but
> the versioned virtual Provides is preferred): please, when you plan to push
> updates for your packages, ALWAYS CHECK what version of Qt your package got
> built against and DO NOT PUSH your update to stable before that version of Qt
> goes stable! A package built against Qt 4.6 WILL NOT WORK AT ALL with Qt
> 4.5!!! (This is always the case, Qt is backwards- but not forwards-
> compatible.)


-- 
Kalev