"Invalid value for -O" build failure(s) — clang 3.6.0

clang refuses the command:
$ clang -O6 main.c
(gcc accepts it even if it is meaning less)
PackageVersionSupposed error messageFull log Bug report
gamera 3.4.1+svn1423-4error: invalid integral value 'g' in '-Og' Log

1 errors