Why does adding /usr/lib32 to LD_LIBRARY_PATH break 64-bit binaries?

[Alexander Sack]

On Thu, Oct 23, 2008 at 10:09 PM, Alexander Kabaev <kabaev at gmail.com> wrote:
> On Thu, 23 Oct 2008 21:48:47 -0400
> "Alexander Sack" <pisymbol at gmail.com> wrote:
>
>> Thanks, comments most appreciated.  Damn, I was looking for someone to
>> go "a ha, you can't do this because...."  Alright, let me see why rtld
>> on 6.1-amd64 is picking up /usr/lib32 stuff for a native 64-bit binary
>> via debugging techniques. This seems very very wrong to me.  I mean if
>> /usr/lib is in my LD_LIBRARY_PATH and it comes before /usr/lib the
>> /usr/lib32 *should* be innocuous, right?
>>
>> Feel free to use that last statement on my epitaph!  :D
>>
> LD_LIBRARY_PATH is for native 64bit rtld. If you want a specific path
> added for use by 32-bit ld-elf.so.1 only, use LD_32_LIBRARY_PATH.
>
> Said that, your problem is likely caused by the fact that there is
> no /lib32, only /usr/lib32. So if 64-bit library lives in /lib,
> your LD_LIBRARY_PATH will cause loader to find its 32-bit equivalent
> in /usr/lib32 first.
>
> Try LD_LIBRARY_PATH=/lib:/usr/lib:/usr/lib32:/usr/lib64 for better
> results.

Yes I figured that out on my own but my question still exists, why
isn't /usr/lib similar in format to /usr/lib32 though with respect to
major numbers?  Actually now that I re-read your paragraph I suppose
this isn't such a bad idea but for some reason I believe that if you
have /usr/lib before /usr/lib32 it should *just* work.

-aps