on FreeBSD Kea should prefer clang instead of gcc
as it fails on linking with log4cplus.
It could be done in configure.ac this way:
if uname="FreeBSD"
# override configure preference for gcc
AC_PROG_CC(clang llvm-gcc gcc)
AC_PROG_CXX(clang++ llvm-g++ g++)
else
AC_PROG_CC
AC_PROG_CXX
fi
this is based on: https://lists.freebsd.org/pipermail/freebsd-toolchain/2013-September/001038.html