pkgconf

pkgconf is a tool and framework (libpkgconf) which provides compiler and linker configuration for development frameworks.

general summary

pkgconf is a program which helps to configure compiler and linker flags for development frameworks.

It is similar to pkg-config, but was written from scratch in the summer of 2011 to replace pkg-config, which for a while needed itself to build itself (they have since included a 'stripped down copy of glib 2.0') Since then we have worked on improving pkg-config for embedded use.

If you're wondering what pkg-config is useful for, you might find the tutorial/guide docs for legacy pkg-config useful.

libpkgconf is a library which allows other tools, such as compilers and IDEs, to discover and use frameworks configured by pkgconf.

usage

Implementations of pkg-config, such as pkgconf, are typically used with the PKG_CHECK_MODULES autoconf macro. As far as we know, pkgconf is compatible with all known variations of this macro. pkgconf detects at runtime whether or not it was started as 'pkg-config', and if so, attempts to set program options such that its behaviour is similar.

In terms of the autoconf macro, it is possible to specify the PKG_CONFIG environment variable, so that you can test pkgconf without overwriting your pkg-config binary. Some other build systems may also respect the PKG_CONFIG environment variable.

To set the environment variable on the bourne shell and clones (i.e. bash), you can run:

$ export PKG_CONFIG=/usr/bin/pkgconf

technical design (why pkgconf is better for distros)

pkgconf builds an acyclic directed dependency graph. This allows for the user to more conservatively link their binaries -- which may be helpful in some environments, such as when prelink(1) is being used. As a result of building a directed dependency graph designed for the specific problem domain provided by the user, more accurate dependencies can be determined. pkg-config, on the other hand builds a database of all known pkg-config files on the system before attempting to resolve dependencies, which is a considerably slower and less efficient design.

pkgconf also does not bundle any third-party libraries or depend on any third-party libraries, making it a great tool for embedded systems and distributions with security concerns.

other differences verses pkg-config

As previously mentioned, pkgconf makes optimizations to the linker flags in both the case of static and shared linking in order to avoid overlinking binaries and also simplifies the CFLAGS and LIBS output of the pkgconf tool for improved readability.

This functionality depends on the pkg-config module properly declaring it's dependency tree instead of using Libs and Cflags fields to directly link against other modules which have pkg-config metadata files installed.

Doing so is discouraged by the freedesktop tutorial anyway.

Beyond that, we do not provide bug-level compatibility with pkg-config. What that means is, if you feel that there is a legitimate regression verses pkg-config, do let us know, but also make sure that the .pc files are valid and follow the rules of the pkg-config tutortial, as most likely fixing them to follow the specified rules will solve the problem.

compiling

pkgconf is basically compiled the same way any other autotools-based project is compiled:

$ ./configure
$ make
$ sudo make install

If you are installing pkgconf into a custom prefix, such as /opt/pkgconf, you will likely want to define the default system includedir and libdir for your toolchain. To do this, use the --with-system-includedir and --with-system-libdir configure flags like so:

$ ./configure \
     --prefix=/opt/pkgconf \
     --with-system-libdir=/lib:/usr/lib \
     --with-system-includedir=/usr/include
$ make
$ sudo make install

If you want pkgconf to be used when you invoke pkg-config, you should install a symlink for this. We do not do this for you, as we believe it is better for vendors to make this determination themselves.

$ ln -sf /usr/bin/pkgconf /usr/bin/pkg-config

release tarballs

Release tarballs are available at http://rabbit.dereferenced.org/~nenolod/distfiles/.

reporting bugs

See https://github.com/pkgconf/pkgconf/issues.

Also you can contact us at #pkgconf at irc.freenode.net.