Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.7.2-5' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --with-arch-32=i586 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.2 (Debian 4.7.2-5) 
In file included from ../eval.c:14:0:
../eval.c: In function ‘setup_exception’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../eval.c:515:27: note: ‘_th’ was declared here
../eval.c:467:17: warning: ‘file’ may be used uninitialized in this function [-Wmaybe-uninitialized]
In file included from ../eval.c:31:0:
../eval_jump.c: In function ‘rb_exec_end_proc’:
../eval_jump.c:129:18: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../eval_jump.c:128:9: warning: ‘th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
In file included from ../eval.c:14:0:
../eval.c: In function ‘ruby_setup’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../eval.c:55:30: note: ‘_th’ was declared here
../eval.c: In function ‘ruby_options’:
../eval.c:1688:1: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../eval.c:97:30: note: ‘_th’ was declared here
In file included from ../load.c:9:0:
../load.c: In function ‘rb_load_internal0’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../load.c:604:30: note: ‘_th’ was declared here
In file included from ../proc.c:12:0:
../proc.c: In function ‘rb_method_call_with_block’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../proc.c:1883:30: note: ‘_th’ was declared here
../proc.c:1902:21: warning: ‘data’ may be used uninitialized in this function [-Wmaybe-uninitialized]
In file included from ../vm.c:84:0:
../vm_eval.c: In function ‘rb_iterate’:
../vm_eval.c:1120:14: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../vm_eval.c:1056:18: warning: ‘th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../vm_eval.c:1068:18: warning: ‘node’ may be used uninitialized in this function [-Wmaybe-uninitialized]
In file included from ../vm.c:84:0:
../vm_eval.c: In function ‘eval_string_with_cref’:
../vm_eval.c:1288:14: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
In file included from ../vm.c:20:0:
../vm_eval.c: In function ‘rb_eval_cmd’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
In file included from ../vm.c:84:0:
../vm_eval.c:1497:30: note: ‘_th’ was declared here
In file included from ../vm.c:20:0:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
In file included from ../vm.c:84:0:
../vm_eval.c:1482:27: note: ‘_th’ was declared here
../vm_backtrace.c: In function ‘rb_debug_inspector_open’:
../vm_backtrace.c:1194:14: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
In file included from ../vm_trace.c:30:0:
../vm_trace.c: In function ‘exec_hooks_protected’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../vm_trace.c:303:30: note: ‘_th’ was declared here
In file included from ../vm_trace.c:30:0:
../vm_trace.c: In function ‘rb_suppress_tracing’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../vm_trace.c:404:30: note: ‘_th’ was declared here
In file included from ../thread.c:60:0:
../thread.c: In function ‘rb_thread_s_handle_interrupt’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../thread.c:1758:30: note: ‘_th’ was declared here
In file included from ../thread.c:60:0:
../thread.c: In function ‘rb_thread_terminate_all’:
../eval_intern.h:136:15: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../thread.c:441:27: note: ‘_th’ was declared here
../cont.c: In function ‘cont_capture’:
../cont.c:515:14: warning: ‘cont’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../cont.c: In function ‘rb_fiber_start’:
../cont.c:1295:14: warning: ‘_th’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../cont.c:1286:15: warning: ‘cont’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../cont.c:1261:58: warning: ‘fib’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../cont.c:1273:17: note: ‘fib’ was declared here