In the meantime I've found this discussion:

https://trac.clfs.org/ticket/1098

Could it be that this behaviour is triggered by 'glibc'!?

On 14.05.2020 00:38, Matthias Fischer wrote:
> Hi,
> 
> on a fresh Core 144 / x86_64 install, running without any seen problems,
> I get these "messages":
> 
> ...
> ldconfig: Path `/lib64' given more than once
> ldconfig: Can't stat /libx32: No such file or directory
> ldconfig: Path `/usr/lib64' given more than once
> ldconfig: Can't stat /usr/libx32: No such file or directory
> ...
> 
> when I run 'ldconfig -v'.
> 
> This is new to me - I'm searching, but haven't found the reason yet. And
> I'd like to know...
> 
> Any ideas?
> 
> Thanks in advance!
> 
> Best,
> 
> Matthias
>