/etc/ld.so.conf missing Qt library directory

[Jakub Jelinek]

On Fri, Oct 15, 2004 at 03:22:22AM -0400, Olu Akins wrote:
> checking for Qt... configure: error: Qt (>= Qt 3.0) (library qt-mt) not found. 
> Please check your installation!
> For more details about this problem, look at the end of config.log.
> Make sure that you have compiled Qt with thread support!
> 
> after adding the library directory /usr/lib/qt-3.3/lib/, still unable to 
> compile any program depend on Qt

The Qt dir is not present in /etc/ld.so.conf, but /etc/ld.so.conf
has:
include ld.so.conf.d/*.conf

and /etc/ld.so.conf.d/qt-i386.conf has the /usr/lib/qt-3.3/lib
directory in it.
But, ld.so.conf is used solely by ldconfig or ld for -rpath-link
purposes only (i.e. if you say have libfoo.so in /foo/bar/baz/
directory and libfoo.so is linked against libqt-*.so.*,
you can do g++ ... -L /foo/bar/baz/ -lfoo and don't have to
manually specify -Wl,-rpath-link,/usr/lib/qt-3.3/lib/).

But if you want to link against libqt-mt*.so*, you need to
pass the corresponding -L/usr/lib/qt-3.3/lib/ to the linker
(or have the configure scripts do that for you; in that case
they are usually looking for $QTDIR environment variable - 
the setup of this variable is done in /etc/profile.d/qt.sh,
which is part of qt-devel, though if you installed qt-devel
after logging in, you need to source that script to set the
variable up).

	Jakub