The FreeBSD ports framework supports parallel building using multiple make sub-processes, which allows SMP systems to utilize all of their available CPU power, allowing port builds to be faster and more effective.

This is achieved by passing -jX flag to make(1) running on vendor code. Unfortunately, not all ports handle parallel building well. Therefore it is required to explicitly enable this feature by adding MAKE_JOBS_SAFE=yes somewhere below the dependency declaration section of the Makefile.

Another option for controlling this feature from the maintainer's point of view is the MAKE_JOBS_UNSAFE=yes variable. It is used when a port is known to be broken with -jX and a user forces the use of multi processor compilations for all ports in /etc/make.conf with the FORCE_MAKE_JOBS=yes variable.

If your port uses GNU make, set USES= gmake.

If your port is an X application that creates Makefile files from Imakefile files using imake, then set USES= imake. This will cause the configure stage to automatically do an xmkmf -a. If the -a flag is a problem for your port, set XMKMF=xmkmf. If the port uses imake but does not understand the install.man target, NO_INSTALL_MANPAGES=yes should be set.

If your port's source Makefile has something else than all as the main build target, set ALL_TARGET accordingly. Same goes for install and INSTALL_TARGET.

If your port uses the configure script to generate Makefile files from Makefile.in files, set GNU_CONFIGURE=yes. If you want to give extra arguments to the configure script (the default argument is --prefix=${PREFIX} --infodir=${PREFIX}/${INFO_PATH} --mandir=${MANPREFIX}/man --build=${CONFIGURE_TARGET}), set those extra arguments in CONFIGURE_ARGS. Extra environment variables can be passed using CONFIGURE_ENV variable.

For ports that use CMake, define USES= cmake, or USES= cmake:outsource to build in a separate directory (see below).

CMake supports the following build profiles: Debug, Release, RelWithDebInfo and MinSizeRel. Debug and Release profiles respect system *FLAGS, RelWithDebInfo and MinSizeRel will set CFLAGS to -O2 -g and -Os -DNDEBUG correspondingly. The lower-cased value of CMAKE_BUILD_TYPE is exported to the PLIST_SUB and should be used if port installs *.cmake files depending on the build type (see deskutils/strigi for an example). Please note that some projects may define their own build profiles and/or force particular build type by setting CMAKE_BUILD_TYPE in CMakeLists.txt files. In order to make a port for such a project respect CFLAGS and WITH_DEBUG, the CMAKE_BUILD_TYPE definitions must be removed from those files.

Most CMake-based projects support an out-of-source method of building. The out-of-source build for a port can be requested by using the :outsource suffix. When enabled, CONFIGURE_WRKSRC, BUILD_WRKSRC and INSTALL_WRKSRC will be set to ${WRKDIR}/.build and this directory will be used to keep all files generated during configuration and build stages, leaving the source directory intact.

If your port uses SCons, define USE_SCONS=yes.

To make third party SConstruct respect everything that is passed to SCons in SCONS_ENV (that is, most importantly, CC/CXX/CFLAGS/CXXFLAGS), patch the SConstruct so build Environment is constructed like this:

It may be then modified with env.Append and env.Replace.