FreeBSD build instructions

[mrrooster]

From the FreeBSD documentation, in the GCC section:

It's probably possible to build the libraries in a way that doesn't require export LD_LIBRARY_PATH=/usr/local/lib/gcc9. If you know how click "edit" and dish.

After installing GCC9, type the following:

export LDFLAGS="-Wl,-rpath=/usr/local/lib/gcc9"

This will ensure the build doesn't require the LD_LIBRARY_PATH variable to be set.