[aur-general] Gcc-6.3: ldd shows wrong symbols

[Stefan Husmann]

Eli Schwartz via aur-general <aur-general at archlinux.org> writes:

> On 06/27/2017 08:56 PM, Stefan Husmann wrote:
>> Hello,
>> 
>> I have put gcc63 to AUR, merely to have a working gcj implemetation,
>
> Wait, isn't there already a gcc6 package in the AUR?
>
It is newer than mine. 
>> something is wrong with it. If I compile anything with it, ldd shows
>> that the resulting binaries have wrong symbols. For  instance,
>> 
>> ldd ~/paketierung/meine_Pakete/fotoxx/pkg/fotoxx/usr/bin/fotoxx |grep -v usr
>>         linux-vdso.so.1 (0x00007ffcbe5cf000)
>>         libstdc++.so.6 => /lib/gcc/x86_64-pc-linux-gnu/6.3.1/libstdc++.so.6 (0x00007fd4fb0e7000)
>>         libgcc_s.so.1 => /lib/gcc/x86_64-pc-linux-gnu/6.3.1/libgcc_s.so.1 (0x00007fd4fabbe000)
>>         /lib64/ld-linux-x86-64.so.2 (0x00007fd4fe8d6000)
>> 
>> IMHO it should be libstdc++.so.6 => /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.1/libstdc++.so.6
>> 
>> What am I doing wrong? I do not know how to fix this.
>
> How does the resulting binary have "wrong symbols" as a result of where
> the linux dynamic linker resolves a soname without a path to? Also are
> you aware that on Linux, "/lib" is a symbolic link to "usr/lib" and
> therefore your preferred result resolves to the same filename?
Yes, I am aware of that.

>Also, gcc
> 7 was released to [core] a month ago.
It does not come with gcj anymore, they dropped it.
>
> A better question would be, why is the linker looking in
> /usr/lib/gcc/$CHOST/$gccver/ instead of /usr/lib? And, do you have some
> sort of actual issue whereby any of this would be relevant?
>
Running pdftk without having LD_LIBRRY_PATH set to
$LD_LIBRARY_PATH:/lib/gcc/x86_64-pc-linux-gnu/6.3.1/ results in

pdftk: error while loading shared libraries: libgcj.so.17: cannot open shared object file: No such file or directory

> And, I think you are lying about the command you ran, not that it really
> matters as the command wouldn't show anything interesting anyway.
> Namely, I think you prefixed it with LD_LIBRARY_PATH="$blah"
>

>> fotoxx is written in c++, but this happens also for programs compiled
>> with gcc or gcj. The pdftk PKGBUILD especially suffers from this, as you
>> can see in the AUR comments. 
>
> The pdftk PKGBUILD and others suffer from being run with a custom
> LD_LIBRARY_PATH and therefore having the dynamic loader match sonames to
> non-default shared library filenames? Or something else?
>
see above
> -- 
> Eli Schwartz