---

title: Distributors short-description: Guide for distributors using meson ...

Using Meson

Distro packagers usually want total control on the build flags used. Meson supports this use case natively. The commands needed to build and install Meson projects are the following.

$ cd /path/to/source/root
$ CFLAGS=... CXXFLAGS=... LDFLAGS=.. meson --prefix /usr --buildtype=plain builddir
$ ninja -v -C builddir
$ ninja -C builddir test
$ DESTDIR=/path/to/staging/root ninja -C builddir install

The command line switch --buildtype=plain tells Meson not to add its own flags to the command line. This gives the packager total control on used flags.

This is very similar to other build systems. The only difference is that the DESTDIR variable is passed as an environment variable rather than as an argument to ninja install.

As distro builds happen always from scratch, we recommend you to enable unity builds whenever possible on your packages because they are faster and produce better code.

Overriding Default Directories

Many distributions differ in their directory layout so as of Meson 0.45.0 we expose an easy method of overriding the default behavior. The reason you would want to override these is not for packages it is for users building software on the distro as they expect meson without any specified arguments to go into the right location. In build scripts for packages it should explicitly set any directories especially prefix.

Inside the mesonbuild python module you can create a distro_directories.py file and meson will import the default_directories dictionary from that and override the internal defaults. As such it can do any arbitrary task such as checking the architecture at runtime.

The list of these directories as well as their descriptions and defaults can be found in meson --help or alternatively in default_directories in mesonlib.py.

Some simple examples:

default_directories = {
  'libdir': 'lib',  # Avoid the lib64 heuristics in meson
  'libexecdir': 'lib',  # Some distros don't have a dedicated libexec
}

import platform

if platform.machine() in ('x86_64', 'aarch64'):
    libdir = 'lib64'
else:
    libdir = 'lib'


default_directories = {
  'libdir': libdir,
}

import subprocess

pc = subprocess.Popen(['dpkg-architecture', '-qDEB_HOST_MULTIARCH'],
                      stdout=subprocess.PIPE,
                      stderr=subprocess.DEVNULL)
(stdo, _) = pc.communicate()
assert pc.returncode == 0
archpath = stdo.decode().strip()
libdir = 'lib/' + archpath

default_directories = {
  'libdir': libdir,
}