Library search path problem on x86_64 machines (lib64 vs lib)

Vincent Lefevre
Tue Nov 30 14:36:00 GMT 2010

On 2010-11-30 14:22:03 +0000, Jonathan Wakely wrote:
> On 30 November 2010 12:53, Vincent Lefevre wrote:
> > I've found a library search path problem with GCC 4.3.1. I wonder
> > whether this is a bug in GCC or in Debian's symbolic link settings
> > and what the current status is (with new GCC versions).
> >
> > The summary:
> >
> > GCC searches all .../lib64 directories, then all .../lib directories,
> > but Debian has a symbolic link /usr/lib64 -> /usr/lib, which means
> > that /usr/lib will have the precedence over all the other .../lib
> > directories. This is wrong!
> Since it is the same as /usr/lib64, surely it *already* has precedence
> over the other lib dirs anyway, because /usr/lib64 will have been
> searched earlier, so I don't see why it causes a problem.

The point is that
  * either /usr/lib64 shouldn't exist at all,
  * or .../lib64 directories shouldn't be searched at all
    (this is what Debian's GCC 4.3.2 does),
  * or the search path order should be changed, e.g. to something
    like: dir1/../lib64 dir1 dir2/../lib64 dir2 ...

"make install" typically installs libraries in $prefix/lib, not
$prefix/lib64, so that the existence of lib64 doesn't make sense!

Vincent Lefèvre <> - Web: <>
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Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon)

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