Eu tenho esse tipo de mensagem quando inicio o gdb:

$ gdb a.out 
GNU gdb 6.3.50-20050815 (Apple version gdb-1708) (Thu Nov  3 21:59:02 UTC 2011)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
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This GDB was configured as "x86_64-apple-darwin"...Reading symbols for shared libraries .
warning: Could not find object file "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_gcc47/gcc47/work/build/x86_64-apple-darwin11/libstdc++-v3/src/../libsupc++/.libs/libsupc++convenience.a(array_type_info.o)" - no debug information available for "../../../../gcc-4.7.0/libstdc++-v3/libsupc++/array_type_info.cc".


warning: Could not find object file "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_gcc47/gcc47/work/build/x86_64-apple-darwin11/libstdc++-v3/src/../libsupc++/.libs/libsupc++convenience.a(bad_alloc.o)" - no debug information available for "../../../../gcc-4.7.0/libstdc++-v3/libsupc++/bad_alloc.cc".

Parece que eu preciso buscar novamente o libstdc ++, mas como com macports?