ld finds some libraries, but not others (REVISED)

[Jonathan Ryshpan]

A build is failing with the error cannot find <library> for libraries
that are, in fact present on the system.

I made a very simple test bed, consisting of the empty file conftest.c,
which I attempt to compile and link with various libraries.  All the
libraries are in /usr/lib64.  Sometimes the compilation fails with
        undefined reference to `main'
which is what I would expect, but often it fails with
        cannot find -l<whatever>
I have no idea what's happening.  Can anyone explain?

Here's an example of what's going on.  This is a listing of some files
in /usr/lib64:
        $ ll libICE.so* libgd.so* libkate.so* libkblog.so.*
        lrwxrwxrwx. 1 root root     15 Nov  9 18:28 libICE.so -> libICE.so.6.3.0*
        lrwxrwxrwx. 1 root root     15 Nov  9 08:02 libICE.so.6 -> libICE.so.6.3.0*
        -rwxr-xr-x. 1 root root  98328 Jun 21 09:37 libICE.so.6.3.0*
        lrwxrwxrwx. 1 root root     14 Nov  9 08:14 libgd.so.2 -> libgd.so.2.0.0*
        -rwxr-xr-x. 1 root root 278048 Oct 26 20:15 libgd.so.2.0.0*
        lrwxrwxrwx. 1 root root     16 Nov  9 08:06 libkate.so.1 -> libkate.so.1.2.1*
        -rwxr-xr-x. 1 root root  75640 Mar  7  2011 libkate.so.1.2.1*
        lrwxrwxrwx. 1 root root     17 Nov 13 09:03 libkblog.so.4 -> libkblog.so.4.7.0*
        -rwxr-xr-x. 1 root root 312960 Nov  4 10:05 libkblog.so.4.7.0*
And here's a attempt to compile the dummy linking to them:
        $ gcc -o conftest -g -O2 conftest.c -lICE
        /usr/lib/gcc/x86_64-redhat-linux/4.6.2/../../../../lib64/crt1.o: In function `_start':
        (.text+0x20): undefined reference to `main'
        collect2: ld returned 1 exit status
        1034 wview-5.19.0 $ gcc -o conftest -g -O2 conftest.c -lgd
        /usr/bin/ld: cannot find -lgd
        collect2: ld returned 1 exit status
        1035 wview-5.19.0 $ gcc -o conftest -g -O2 conftest.c -lkate
        /usr/bin/ld: cannot find -lkate
        collect2: ld returned 1 exit status
        1036 wview-5.19.0 $ gcc -o conftest -g -O2 conftest.c -lkblog
        /usr/lib/gcc/x86_64-redhat-linux/4.6.2/../../../../lib64/crt1.o: In function `_start':
        (.text+0x20): undefined reference to `main'
        collect2: ld returned 1 exit status

System information:
        Fedora-16 with all updates running on 4 cpu x86_64 hardware
        $ gcc -v
                Using built-in specs.
                COLLECT_GCC=gcc
                COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.6.2/lto-wrapper
                Target: x86_64-redhat-linux
                Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --enable-languages=c,c++,objc,obj-c++,java,fortran,ada,go,lto --enable-plugin --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
                Thread model: posix
                gcc version 4.6.2 20111027 (Red Hat 4.6.2-1) (GCC) 
        $ ld -v
                GNU ld version 2.21.53.0.1-2.fc16 20110716