New features (in development)

Cargo features are resolved globally

When configuring a Cargo dependency, Meson will now resolve its complete dependency tree and feature set before generating the subproject AST. This solves many cases of Cargo subprojects being configured with missing features that the main project had to enable by hand using e.g. default_options: ['foo-rs:feature-default=true'].

Note that there could still be issues in the case there are multiple Cargo entry points. That happens if the main Meson project makes multiple dependency() calls for different Cargo crates that have common dependencies.

Breaks: This change removes per feature Meson options that were previously possible to set as shown above or from command line -Dfoo-rs:feature-foo=true.

Meson can run "clippy" on Rust projects

Meson now defines a clippy target if the project uses the Rust programming language. The target runs clippy on all Rust sources, using the clippy-driver program from the same Rust toolchain as the rustc compiler.

Using clippy-driver as the Rust compiler will now emit a warning, as it is not meant to be a general-purpose compiler front-end.

Devenv support in external project module

The external project module now setups PATH and LD_LIBRARY_PATH to be able to run programs.

@BINDIR@ is now substitued in arguments and '--bindir=@PREFIX@/@BINDIR@' default argument have been added.

Fixed sizeof and find_library methods for Fortran compilers

The implementation of the .sizeof() method has been fixed for Fortran compilers (it was previously broken since it would try to compile a C code snippet). Note that this functionality requires Fortran 2008 support.

Incidentally this also fixes the .find_library() method for Fortran compilers when the prefer_static built-in option is set to true.

format command now accept stdin argument

You can now use - argument for meson format to read input from stdin instead of reading it from a file.

"machine" entry in target introspection data

The JSON data returned by meson introspect --targets now has a machine entry in each target_sources block. The new entry can be one of build or host for compiler-built targets, or absent for custom_target targets.

Control the number of child processes with an environment variable

Previously, meson test checked the MESON_TESTTHREADS variable to control the amount of parallel jobs to run; this was useful when meson test is invoked through ninja test for example. With this version, a new variable MESON_NUM_PROCESSES is supported with a broader scope: in addition to meson test, it is also used by the external_project module and by Ninja targets that invoke clang-tidy, clang-format and clippy.

Install vcs_tag() output

vcs_tag() now has install, install_dir, install_tag and install_mode keyword arguments to install the generated file.