http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50224
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-08-29 13:14:01 UTC --- I've just tested with the official 4.6.1 release: gcc version 4.6.1 (GCC) and the 4.6-20110819 snapshot: gcc version 4.6.2 20110819 (prerelease) (GCC) and the tip of the 4.6 branch: gcc version 4.6.2 20110829 (prerelease) [gcc-4_6-branch revision 178215] (GCC) and there's no warning or error, so I don't know what the ArchLinux package is based on. It looks like the 20110819 snapshot with a misleading BASE-VER, but that shouldn't warn.