Meson Build System

Warnings

• deprecated The `meson.build_root()` and `meson.source_root()` functions are deprecated as they often cause issues in subprojects by pointing to the parent project's root.
  Fix: Use `meson.current_source_dir()`, `meson.current_build_dir()`, `meson.project_source_root()`, or `meson.project_build_root()` instead, which provide better subproject isolation.
• deprecated Coercing string values (e.g., `'false'`) to boolean types in the `option()` function is deprecated and will result in a warning.
  Fix: Pass explicit boolean values (`true` or `false`) to `option()` for boolean types.
• breaking Using a colon (':') in test names is deprecated and will be replaced with an underscore ('_') internally, to avoid conflicts with the `subproject:testname` syntax for running subproject-specific tests.
  Fix: Rename tests to avoid colons in their names.
• gotcha The `meson dist` command will error if the Git repository contains uncommitted changes. This is a stricter behavior to prevent accidental releases of non-committed code.
  Fix: Commit all changes before running `meson dist`, or explicitly use the `--allow-dirty` command-line option if you intend to create a distribution from a dirty working tree.
• breaking Meson 1.10.0 introduced a 'platform' naming scheme for libraries, which will eventually become the default, potentially altering library filenames (e.g., on Windows, static libraries might change from `.a` to `.lib`, and import libraries from `.lib` to `.dll.lib`).
  Fix: Projects relying on specific legacy library naming should be aware of the `namingscheme` option. Consider explicitly setting `namingscheme: 'legacy'` in your `project()` call if you depend on old behavior, or adapt to `platform` naming.
• gotcha Performance regression in `pkg-config` dependency lookup in Meson 1.10.0, potentially making `meson setup` significantly slower for projects with many `pkg-config` dependencies due to new linkability checks.
  Fix: This is an ongoing issue reported in the Meson GitHub repository. No direct fix for users at this time, but awareness is key for debugging slow configure times.

Install

• pip install meson Install using pip
• sudo apt-get install python3 ninja-build meson Debian/Ubuntu (may be outdated)

Imports

• Meson DSL

  Meson is primarily used via its command-line interface and build definition files (e.g., meson.build), not typically through direct Python imports for general build orchestration. Python modules within Meson's DSL are imported using the `import()` function (e.g., `python = import('python')`).

  Meson build files use their own DSL. While Meson is written in Python, direct programmatic use of the 'meson' Python package as a library is not the primary way to interact with the build system for end-user projects. For Python package integration, `meson-python` is the recommended PEP 517 backend.

Quickstart

This quickstart demonstrates how to create a simple C 'Hello World' project with Meson. It involves defining the project and an executable in `meson.build`, configuring the build directory, compiling the project, running the executable, and finally installing it. Meson enforces out-of-source builds, meaning all build artifacts are placed in a separate build directory (e.g., `builddir`).

mkdir myproject
cd myproject
echo '#include <stdio.h>\nint main() { printf("Hello from Meson!\n"); return 0; }' > main.c
echo "project('hello_meson', 'c')\nexecutable('hello', 'main.c', install: true)" > meson.build

meson setup builddir
meson compile -C builddir
./builddir/hello
meson install -C builddir