The miscompiled file is apt-pkg/contrib/error.cc which , the one that contains the varargs using functions in the backtrace.
Compiling that object with gcc 4.5 -O2, gcc 4.6 at -O0 or -O1 results in good code generated.
Using gcc 4.6 at -O2 causes a segfault.
I'll provide more info shortly.
The miscompiled file is apt-pkg/ contrib/ error.cc which , the one that contains the varargs using functions in the backtrace.
Compiling that object with gcc 4.5 -O2, gcc 4.6 at -O0 or -O1 results in good code generated.
Using gcc 4.6 at -O2 causes a segfault.
I'll provide more info shortly.