configure breaks CXXFLAGS

When "-ggdb" is among the CXXFLAGS in the environment, configure will remove the "-g" but leave the "gdb" in place, causing compiler errors. The corresponding line was introduced in r21 of the SVN repository:
CXXFLAGS=`echo $CXXFLAGS | sed -e "s/-g//" -e "s/-O2//"`

As a workaround, you might use this line instead, in order to include any non-space characters following the -g:
CXXFLAGS=`echo $CXXFLAGS | sed -e "s/-g\\S*//" -e "s/-O2//"`

I'm not convinced that manipulating the CXXFLAGS here is a good idea, though. If the user specified CXXFLAGS with debug options, what's the point in removing them again? Configure should imo never try to be more clever than the user calling it. The commit log message doesn't give an indication as to the intention of this line, either.

And even if there is a reason to remove the -g, and even if you apply my patch to address the -ggdb case, there might be strange cases like "-I/usr/lib-gnu" where the -g doesn't have the meaning you expect it to have. So you would need to take whitespace into account as well, and so on. The point I'm trying to make here is that this CXXFLAGS modification is a hack, and you are probably better off removing it than fixing it.