[R-SIG-Mac] duplicate dylib ... libgcc_s.1.dylib

[Hans-Peter]

Hello R-Mac experts,

When I build a shared object (R CMD SHLIB hellocalc.c) I get a warning
about duplicate libgcc_s.1.dylib. The generated 'hellocalc.so' can be
loaded and works well but I wonder if I am supposed to do something
(what?) to prevent this warning. There are (few) related questions in
the maillist archive, but in those cases there were errors and not
just warnings.

I also ask because if I do 'R CMD CHECK helloC' the generated
'helloC.so' doesn't work (~cannot load shared library 'helloC.so'
[...]  no suitable image found.  Did find: [...] helloC.so: mach-o,
but wrong architecture) and I am not sure if this has to do something
with the above mentioned warning.

* Mac OS X 10.5.4 (9E17) - R version 2.7.1 (2008-06-23) i386-apple-darwin8.10.1

* libgcc_s.1.dylib are located on the following places on my system:
   /Developer/SDKs/MacOSX10.4u.sdk/usr/lib/libgcc_s.1.dylib
   /Developer/SDKs/MacOSX10.5.sdk/usr/lib/libgcc_s.1.dylib
   /Library/Frameworks/R.framework/Versions/2.7/Resources/lib/libgcc_s.1.dylib
   /usr/lib/libgcc_s.1.dylib
   /usr/local/lib/libgcc_s.1.dylib

* Warning message:
Macintosh:src chappi$ R CMD SHLIB hellocalc.c
gcc -arch i386 -isysroot /Developer/SDKs/MacOSX10.4u.sdk
-mmacosx-version-min=10.4 -std=gnu99
-I/Library/Frameworks/R.framework/Resources/include
-I/Library/Frameworks/R.framework/Resources/include/i386  -msse3
-fPIC  -g -O2 -march=nocona -c hellocalc.c -o hellocalc.o
gcc -arch i386 -isysroot /Developer/SDKs/MacOSX10.4u.sdk
-mmacosx-version-min=10.4 -std=gnu99 -dynamiclib
-Wl,-headerpad_max_install_names -mmacosx-version-min=10.4 -undefined
dynamic_lookup -single_module -multiply_defined suppress
-L/usr/local/lib -o hellocalc.so hellocalc.o
-F/Library/Frameworks/R.framework/.. -framework R -Wl,-framework
-Wl,CoreFoundation
ld: warning, duplicate dylib
/Developer/SDKs/MacOSX10.4u.sdk/usr/local/lib/libgcc_s.1.dylib

Thank you for your help,
Hans-Peter