Re: Danger in installing new Qt libraries? Rh7.3
From: Ryan Reich (ryanr_at_uchicago.edu)
Date: Mon, 15 Mar 2004 08:04:18 -0600
> On Mon, 15 Mar 2004 11:57:03 +0200, Stefan Viljoen wrote:
>> Is there any way to compile the KDE program requiring the newer Qt
>> version without destroying my KDE installation? Can I for example,
>> compile a binary using the "new" Qt library and run it inside the
>> "old" KDE, forcing it to call/use the new library?
> But in order to compile the new KDE application in the first place it
> would need to locate the newer Qt libraries, and they'd need to be
> carefully installed to avoid treading on your existing version. I guess
> it should be possible to perform some surgery on the Qt tarball and have
> it installed in your own unique location, but I still reckon you'll hit
> problems because of the basic system library support that version of Qt
> would expect. One problem piled upon another! :( I suspect the best
> situation you'd arrive at would be similar to expecting a Win16 OS to
> execute a Win32 application.
This is not necessarily true; or at least, it's not as bad as you make it
sound. If he's compiling from source he won't have some RPM which just
places the files where it wants. All modern software allows you to run
'configure' and pass it, among other things the '--prefix=' directive.
Have it put the new Qt in something like '/home/qt' or wherever there's
space and no old Qt. Then when recompiling KDE, check if its 'configure'
allows you to specify 'qtdir' or something like that. I believe there is
an environment variable 'QTDIR' that serves this purpose, actually. If you
also specify '--prefix=/home/kde' or some such, there will be no conflicts
either with system libraries, installed older versions, or even starting
up, so long as you make sure to run '/home/kde/kdm' rather than
'/path/to/old/kde/kdm' at boot.
> There have been huge developments in Qt and KDE since Redhat 7.3 was a
> current distribution - and Linux itself of course - so really, I think
> your safest option would be to upgrade to a more current distribution.
> I'm out of touch with Redhat's current offerings, but I'd upgraded an
> original Redhat 6.0 installation through their various releases to 7.3
> with nothing dropping off along the way. Actually a cheap way of
> avoiding upgrade problems is to install a second hard disk, if possible,
> and use that as the base for a new installation. Setting up a
> dual/multiboot system is easily done and your original installation
> remains untouched.
I agree, however, that rather than patching a dinosaur he should just
replace it. I didn't use Red Hat, but I know that Mandrake has a
completely painless upgrade process even for cross-version upgrades (8.2 to
9.0, for example). The second hard disk is a good idea.
-- Ryan Reich firstname.lastname@example.org