meson: Usage, Options & Common CI Errors

meson configures a project from meson.build and builds it via ninja.

meson is the modern alternative to autotools/CMake for C/C++ and others. The CI flow is setup then compile; the recurring errors are re-running setup on an existing build dir and missing pkg-config dependencies during configure.

What it does

meson reads a meson.build description, configures a build directory (resolving dependencies, often via pkg-config), and then builds through ninja. It emphasizes fast, reproducible, out-of-source builds with a simple DSL.

Common usage

Terminal

meson setup build                        # configure
meson setup build --buildtype=release
meson compile -C build                   # build (wraps ninja)
meson test -C build                      # run the test suite
meson setup --reconfigure build          # re-run on existing dir

Options

Command / flag	What it does
setup <dir>	Configure a build directory
compile -C <dir>	Build (portable wrapper over ninja)
test -C <dir>	Run the project tests
--buildtype=release\|debug	Set optimization/debug profile
--reconfigure / --wipe	Reconfigure / wipe + reconfigure
-D<opt>=<val>	Set a project or built-in option

Common errors in CI

"Directory already configured" / "Build directory already exists" - meson setup refuses to overwrite; use meson setup --reconfigure build (or --wipe) on cache restore. "Dependency ‘foo’ not found, tried pkgconfig" means the .pc file is missing - install the -dev package or set PKG_CONFIG_PATH. "Program ‘ninja’ not found" - install ninja-build. Pin meson via pip in CI; distro meson is often too old for newer meson.build syntax.