DOC adds instructions for building on FreeBSD
@@ -148,6 +148,30 @@ Then you need to set the following environment variables::
Finally you can build the package using the standard command.
+FreeBSD
+-------
+
+The clang compiler included in FreeBSD 12.0 and 11.2 base systems does not
+include OpenMP support. You need to install the `openmp` library from packages
+(or ports)::
+
+ sudo pkg install openmp
+
+This will install header files in ``/usr/local/include`` and libs in
+``/usr/local/lib``. Since these directories are not searched by default, you
+can set the environment variables to these locations::
+
+ export CFLAGS="$CFLAGS -I/usr/local/include"
+ export CXXFLAGS="$CXXFLAGS -I/usr/local/include"
+ export LDFLAGS="$LDFLAGS -L/usr/local/lib -lomp"
+ export DYLD_LIBRARY_PATH=/usr/local/lib
+
+Finally you can build the package using the standard command.
+
+For the upcomming FreeBSD 12.1 and 11.3 versions, OpenMP will be included in
+the base system and these steps will not be necessary.
+
+
Installing build dependencies
=============================
