[plt-scheme] loading libraries into memory with ffi-lib on osx

Matthew Flatt wrote:
> At Mon, 28 Aug 2006 18:58:10 -0400, Jon Rafkind wrote:
>   
>> So loading libpng12 from the allegro sub-directory is fine on unix but
>> not fine on osx. After more searching I see ___sF is declared in
>> stdio.h, so it must be part of libc or something.
>>     
>
> I think I'm still missing something. What does ___sF have to do with
> anything? Is that one of the undefined symbols?
>
> Maybe showing the specific error message will help me understand.
>
>   
Oh yes, sorry I posted this problem in so many places I forgot what
detail I added where. The error message is this:

resolveUndefined(___sF) in
/Users/jon/tmp/allegro/private/../allegro-4.2.0/lib/macosx/liballeg-4.2.1.dylib
resolveUndefined(___sF) in
/Users/jon/tmp/allegro/private/../allegro-4.2.0/lib/macosx/liballeg-4.2.1.dylib
ffi-lib: couldn't open
"/Users/jon/tmp/allegro/private/../allegro-4.2.0/lib/macosx/liballeg-4.2.1.dylib"
(dlopen(/Users/jon/tmp/allegro/private/../allegro-4.2.0/lib/macosx/liballeg-4.2.1.dylib,
10): symbol not found)
> ^D

Im not sure why things work when I put libpng in /usr/lib or
/usr/local/lib, it seems like the net effect should be the same as
loading libpng into memory via (ffi-lib "allegro-4.2.0/lib/macosx/libpng").