5.7 Dependencies

5.7.1 LIB_DEPENDS

This variable specifies the shared libraries this port depends on. It is a list of lib:dir[:target] tuples where lib is the name of the shared library, dir is the directory in which to find it in case it is not available, and target is the target to call in that directory. For example,

 LIB_DEPENDS=
          jpeg.9:${PORTSDIR}/graphics/jpeg:install

will check for a shared jpeg library with major version 9, and descend into the graphics/jpeg subdirectory of your ports tree to build and install it if it is not found. The target part can be omitted if it is equal to DEPENDS_TARGET (which defaults to install).

The dependency is checked twice, once from within the extract target and then from within the install target. Also, the name of the dependency is put into the package so that pkg_add(1) will automatically install it if it is not on the user's system.

5.7.2 RUN_DEPENDS

This variable specifies executables or files this port depends on during run-time. It is a list of path:dir[:target] tuples where path is the name of the executable or file, dir is the directory in which to find it in case it is not available, and target is the target to call in that directory. If path starts with a slash (/), it is treated as a file and its existence is tested with test -e; otherwise, it is assumed to be an executable, and which -s is used to determine if the program exists in the search path.

For example,

RUN_DEPENDS=   ${LOCALBASE}/etc/innd:${PORTSDIR}/news/inn \
           wish8.0:${PORTSDIR}/x11-toolkits/tk80

will check if the file or directory /usr/local/etc/innd exists, and build and install it from the news/inn subdirectory of the ports tree if it is not found. It will also see if an executable called wish8.0 is in the search path, and descend into the x11-toolkits/tk80 subdirectory of your ports tree to build and install it if it is not found.

The dependency is checked from within the install target. Also, the name of the dependency is put into the package so that pkg_add(1) will automatically install it if it is not on the user's system. The target part can be omitted if it is the same as DEPENDS_TARGET.

5.7.3 BUILD_DEPENDS

This variable specifies executables or files this port requires to build. Like RUN_DEPENDS, it is a list of path:dir[:target] tuples. For example,

 BUILD_DEPENDS=
          unzip:${PORTSDIR}/archivers/unzip

will check for an executable called unzip, and descend into the archivers/unzip subdirectory of your ports tree to build and install it if it is not found.

5.7.4 FETCH_DEPENDS

This variable specifies executables or files this port requires to fetch. Like the previous two, it is a list of path:dir[:target] tuples. For example,

 FETCH_DEPENDS=
          ncftp2:${PORTSDIR}/net/ncftp2

will check for an executable called ncftp2, and descend into the net/ncftp2 subdirectory of your ports tree to build and install it if it is not found.

The dependency is checked from within the fetch target. The target part can be omitted if it is the same as DEPENDS_TARGET.

5.7.5 EXTRACT_DEPENDS

This variable specifies executables or files this port requires for extraction. Like the previous, it is a list of path:dir[:target] tuples. For example,

EXTRACT_DEPENDS=
          unzip:${PORTSDIR}/archivers/unzip

will check for an executable called unzip, and descend into the archivers/unzip subdirectory of your ports tree to build and install it if it is not found.

The dependency is checked from within the extract target. The target part can be omitted if it is the same as DEPENDS_TARGET.

5.7.6 PATCH_DEPENDS

This variable specifies executables or files this port requires to patch. Like the previous, it is a list of path:dir[:target] tuples. For example,

 PATCH_DEPENDS=
          ${NONEXISTENT}:${PORTSDIR}/java/jfc:extract
       

will descend into the java/jfc subdirectory of your ports tree to build and install it if it is not found.

The dependency is checked from within the patch target. The target part can be omitted if it is the same as DEPENDS_TARGET.

5.7.7 DEPENDS

If there is a dependency that does not fall into either of the above categories, or your port requires having the source of the other port extracted in addition to having it installed, then use this variable. This is a list of dir[:target], as there is nothing to check, unlike the previous four. The target part can be omitted if it is the same as DEPENDS_TARGET.

5.7.8 USE_*

A number of variables exist in order to encapsulate common dependencies that many ports have. Although their use is optional, they can help to reduce the verbosity of the port Makefiles. Each of them is styled as USE_*. The usage of these variables is restricted to the port Makefiles and ports/Mk/bsd.*.mk and is not designed to encapsulate user-settable options -- use WITH_* and WITHOUT_* for that purpose.

Define USE_XLIB=yes if your port requires the X Window System to be installed (it is implied by USE_IMAKE). Define USE_GMAKE=yes if your port requires GNU make instead of BSD make. Define USE_AUTOCONF_VER=213 if your port requires GNU autoconf to be run. Define USE_QT_VER=3 if your port uses the latest Qt toolkit. Use USE_PERL5=yes if your port requires version 5 of the perl language. (The last is especially important since some versions of FreeBSD have perl5 as part of the base system while others do not.)

5.7.9 Notes on dependencies

As mentioned above, the default target to call when a dependency is required is DEPENDS_TARGET. It defaults to install. This is a user variable; it is never defined in a port's Makefile. If your port needs a special way to handle a dependency, use the :target part of the *_DEPENDS variables instead of redefining DEPENDS_TARGET.

When you type make clean, its dependencies are automatically cleaned too. If you do not wish this to happen, define the variable NOCLEANDEPENDS in your environment. This may be particularly desirable if the port has something that takes a long time to rebuild in its dependency list, such as KDE, GNOME or Mozilla.

To depend on another port unconditionally, use the variable ${NONEXISTENT} as the first field of BUILD_DEPENDS or RUN_DEPENDS. Use this only when you need to get the source of the other port. You can often save compilation time by specifying the target too. For instance

BUILD_DEPENDS=   ${NONEXISTENT}:${PORTSDIR}/graphics/jpeg:extract

will always descend to the jpeg port and extract it.

Do not use DEPENDS unless there is no other way the behavior you want can be accomplished. It will cause the other port to always be built (and installed, by default), and the dependency will go into the packages as well. If this is really what you need, you should probably write it as BUILD_DEPENDS and RUN_DEPENDS instead--at least the intention will be clear.

5.7.10 Circular dependencies are fatal

The ports building technology does not tolerate circular dependencies. If you introduce one, you will have someone, somewhere in the world, whose FreeBSD installation will break almost immediately, with many others quickly to follow. These can really be hard to detect; if in doubt, before you make that change, make sure you have done the following: cd /usr/ports; make index. That process can be quite slow on older machines, but you may be able to save a large number of people--including yourself-- a lot of grief in the process.