On Sat, 21 Aug 2021, Oleg Smolsky wrote:
>>
>> So, if libtool does not believe that /usr/lib/x86_64-linux-gnu is in
>> the default search path, it adds it.
>>
> Right, and my compiler is in /opt/gcc-11/ and so that addition to
> LD_LIBRARY_PATH is wrong. The system's compiler is older than what we use
> and the forced (older )version of libstdc++ breaks the executable.
You should talk to the person who built and installed this compiler.
I recollect that it was you. :-)
He, he, that's right!
Does
gcc -print-search-dirs
produce correct/useful output for your compiler?
Well, let's see:
libraries: =/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/:/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../x86_64-pc-linux-gnu/lib/x86_64-pc-linux-gnu/11.2.0/:/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../x86_64-pc-linux-gnu/lib/x86_64-linux-gnu/:/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../x86_64-pc-linux-gnu/lib/../lib64/:/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../x86_64-pc-linux-gnu/11.2.0/:/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../x86_64-linux-gnu/:/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../lib64/:/lib/x86_64-pc-linux-gnu/11.2.0/:/lib/x86_64-linux-gnu/:/lib/../lib64/:/usr/lib/x86_64-pc-linux-gnu/11.2.0/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib64/:/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../../x86_64-pc-linux-gnu/lib/:/opt/gcc-11/lib/gcc/x86_64-pc-linux-gnu/11.2.0/../../../:/lib/:/usr/lib/
So, it looks like the '/usr/lib/x86_64-linux-gnu/' bit came straight from that spec...
And yet, the previous GCC build that we used (gcc-10) has a nearly identical output and the associated application build does exhibit the linking issue with libstdc++. Hmm... so I am still struggling to understand the cause and effect here...
If the system's 'ldconfig' is not aware of your compiler's library
installation, then the system will search the normal places for the
libraries unless you add an -rpath option to the build.
Right, each application is linked with -rpath settings to find that right libstdc++ that comes from /opt.
Of course if ldconfig is aware of your compiler's library installation
then that causes problems if you are using multiple compilers.
Right, I never modify the system's ldconfig settings as our toolchain and libs are separate.
My Ubuntu 20 VM has the following (stock) settings:
$ cat /etc/ld.so.conf.d/x86_64-linux-gnu.conf
/usr/local/lib/x86_64-linux-gnu
/lib/x86_64-linux-gnu
/usr/lib/x86_64-linux-gnu
Oleg.