building on FreeBSD 10

[JINMEI Tatuya]

I think figured it out.  We (in ./configure) disable -Werror for some
versions of g++ due to a compiler bug.  All g++ versions on FreeBSD we
are using for development and tests seemingly have this bug, so the
offending warning (it happens) doesn't stop the build.

Since this doesn't happen with other (older/newer) versions of g++, I
suspect this is another bug of g++, and, my guess is that your version
of g++/FreeBSD internally fixes the first bug that would disable
-Werror but doesn't fix the second.

So, my suggestion is to use a different version of g++.  You may also
try to use clang++ (it works on one of our test machines running
FreeBSD 8.1).

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JINMEI, Tatuya
Internet Systems Consortium, Inc.