http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49992
--- Comment #8 from Iain Sandoe <iains at gcc dot gnu.org> 2011-08-08 18:22:38 UTC --- (In reply to comment #7) > > Apparently the key is "--enable-checking=something". > > It is even more subtle (x86_64-apple-darwin10): > > ../work/configure --prefix=/opt/gcc/gcc4.7w > --enable-languages=c,c++,fortran,objc,obj-c++,java --with-gmp=/opt/sw64 > --with-libiconv-prefix=/opt/sw64 --with-system-zlib --with-cloog=/opt/sw64 > --enable-cloog-backend=isl --enable-checking=none > > fails, while > > ../work/configure --prefix=/opt/gcc/gcc4.7w > --enable-languages=c,c++,fortran,objc,obj-c++,java --with-gmp=/opt/sw64 > --with-libiconv-prefix=/opt/sw64 --with-system-zlib --with-cloog=/opt/sw64 > --enable-cloog-backend=isl --enable-checking=yes > > succeeds. This for bootstraps wthout lto enabled: > > [macbook] f90/bug% gfc pr49638_2.f90 -flto > f951: error: LTO support has not been enabled in this configuration the with/without checking will alter the usage of diagnostic routines. It doesn't seem to me to have much to do with lto - it seems a build issue. I.E. one should not be including two different implementations of the diagnostics on the same link line.