http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46749
--- Comment #14 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-12-01 21:23:55 UTC --- Also works with splitting the command into a -c and a link step. Thus, /Users/richard/obj/gcc/xgcc -B/Users/richard/obj/gcc/ /Users/richard/src/trunk/gcc/testsuite/gcc.dg/debug/pr41893-1.c -gdwarf-2 -g1 -flto -fwhole-program -O /Users/richard/src/trunk/gcc/testsuite/gcc.dg/debug/pr41893-2.c -lm -c /Users/richard/obj/gcc/xgcc -B/Users/richard/obj/gcc/ pr41893-1.o -gdwarf-2 -g1 -flto -fwhole-program -O pr41893-2.o -lm -o pr41893-1.exe -flto-partition=none does not fail. -flto-partition=none makes it easier to debug, no make is invocated (it's basically old LTO mode and not WHOPR). darwin doesn't seem to have an 'strace' command (bah). lto-wrapper invokes xgcc: /Users/richard/obj/gcc/lto-wrapper /var/folders/2W/2WzmrwP7EFiRzkWthHumQ++++TM/-Tmp-//cc0Ff4e8.o /var/folders/2W/2WzmrwP7EFiRzkWthHumQ++++TM/-Tmp-//ccWa94cZ.o /Users/richard/obj/gcc/xgcc -xlto -c -mmacosx-version-min=10.6.5 -B /Users/richard/obj/gcc/ -gdwarf-2 -g1 -fwhole-program -O -flto-partition=none -mtune=generic -dumpdir ./ -dumpbase pr41893-1.exe -o /var/folders/2W/2WzmrwP7EFiRzkWthHumQ++++TM/-Tmp-//ccWI2XqX.lto.o /var/folders/2W/2WzmrwP7EFiRzkWthHumQ++++TM/-Tmp-//cc0Ff4e8.o /var/folders/2W/2WzmrwP7EFiRzkWthHumQ++++TM/-Tmp-//ccWa94cZ.o /Users/richard/obj/gcc/collect-ld -dynamic -arch x86_64 -macosx_version_min 10.6.5 -weak_reference_mismatches non-weak -o pr41893-1.exe -lcrt1.10.5.o -L/Users/richard/obj/gcc /var/folders/2W/2WzmrwP7EFiRzkWthHumQ++++TM/-Tmp-//ccWI2XqX.lto.o -v -lgcc_ext.10.5 -lgcc -no_compact_unwind -lSystem @(#)PROGRAM:ld PROJECT:ld64-97.14 Library search paths: /Users/richard/obj/gcc /usr/lib /usr/local/lib Framework search paths: /Library/Frameworks/ /System/Library/Frameworks/ warning: (x86_64) /var/folders/2W/2WzmrwP7EFiRzkWthHumQ++++TM/-Tmp-//ccWI2XqX.lto.o unable to open object file warning: no debug symbols in executable (-arch x86_64)