Eric, So far the smallest test case I can come up with reproduces the "can't find atom for N_GSYM stabs" ld64 linker warning in Darwin is...
#include <testsuite_hooks.h> #include <testsuite_allocator.h> // uneq_allocator as a non-empty allocator. void test01() { bool test __attribute__((unused)) = true; using namespace std; typedef __gnu_test::uneq_allocator<char> my_alloc; typedef deque<char, my_alloc> my_deque; my_deque::size_type size01; my_alloc alloc01(1); my_deque deq01(alloc01); } int main() { test01(); return 0; } ...using the testsuite_hooks.h and testsuite_allocator.h headers from gcc/libstdc++-v3/testsuite/util. Compiling this with... g++-4 -O3 -g -m64 -I. test.cc can't find atom for N_GSYM stabs alloc_map:G(0,3) in /var/tmp//ccPQUmeQ.o ...produces the warning. It's easier to reproduce in gfortran since all you need is to declare a COMMON block. Jack