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+---
+title: Release 0.50.0
+short-description: Release notes for 0.50.0
+...
+
+# New features
+
+## Added `cmake_module_path` and `cmake_args` to dependency
+
+The CMake dependency backend can now make use of existing `Find<name>.cmake`
+files by setting the `CMAKE_MODULE_PATH` with the new `dependency()` property
+`cmake_module_path`. The paths given to `cmake_module_path` should be relative
+to the project source directory.
+
+Furthermore the property `cmake_args` was added to give CMake additional
+parameters.
+
+## Added PGI compiler support
+
+Nvidia / PGI C, C++ and Fortran
+[no-cost](https://www.pgroup.com/products/community.htm) compilers are
+now supported.  They have been tested on Linux so far.
+
+
+
+## Fortran Coarray
+
+Fortran 2008 / 2018 coarray support was added via `dependency('coarray')`
+
+## Libdir defaults to `lib` when cross compiling
+
+Previously `libdir` defaulted to the value of the build machine such
+as `lib/x86_64-linux-gnu`, which is almost always incorrect when cross
+compiling. It now defaults to plain `lib` when cross compiling. Native
+builds remain unchanged and will point to the current system's library
+dir.
+
+## Native and Cross File Paths and Directories
+
+A new `[paths]` section has been added to native and cross files. This
+can be used to set paths such a prefix and libdir in a persistent way.
+
+## Add warning_level 0 option
+
+Adds support for a warning level 0 which does not enable any static
+analysis checks from the compiler
+
+## A builtin target to run clang-format
+
+If you have `clang-format` installed and there is a `.clang-format`
+file in the root of your master project, Meson will generate a run
+target called `clang-format` so you can reformat all files with one
+command:
+
+```meson
+ninja clang-format
+```
+
+
+## Added a .path() method to object return by python.find_installation()
+
+`ExternalProgram` objects as well as the object returned by the
+`python3` module provide this method, but the new python module did
+not.
+
+## Fix ninja console log from generators with multiple output nodes
+
+This resolves ticket #4760 where a generator w/ multiple output nodes
+printed an empty string to the console
+
+## `introspect --buildoptions` can now be used without configured build directory
+
+It is now possible to run `meson introspect --buildoptions /path/to/meson.build`
+without a configured build directory.
+
+Running `--buildoptions` without a build directory produces the same
+output as running it with a freshly configured build directory.
+
+However, this behavior is not guaranteed if subprojects are
+present. Due to internal limitations all subprojects are processed
+even if they are never used in a real meson run.  Because of this
+options for the subprojects can differ.
+
+## `include_directories` accepts a string
+
+The `include_directories` keyword argument now accepts plain strings
+rather than an include directory object. Meson will transparently
+expand it so that a declaration like this:
+
+```meson
+executable(..., include_directories: 'foo')
+```
+
+Is equivalent to this:
+
+```meson
+foo_inc = include_directories('foo')
+executable(..., include_directories: inc)
+```
+
+## Fortran submodule support
+
+Initial support for Fortran ``submodule`` was added, where the submodule is in
+the same or different file than the parent ``module``.
+The submodule hierarchy specified in the source Fortran code `submodule`
+statements are used by Meson to resolve source file dependencies.
+For example:
+
+```fortran
+submodule (ancestor:parent) child
+```
+
+
+## Add subproject_dir to --projectinfo introspection output
+
+This allows applications interfacing with Meson (such as IDEs) to know about
+an overridden subproject directory.
+
+## Find library with its headers
+
+The `find_library()` method can now also verify if the library's headers are
+found in a single call, using the `has_header()` method internally.
+
+```meson
+# Aborts if the 'z' library is found but not its header file
+zlib = find_library('z', has_headers : 'zlib.h')
+# Returns not-found if the 'z' library is found but not its header file
+zlib = find_library('z', has_headers : 'zlib.h', required : false)
+```
+
+Any keyword argument with the `header_` prefix passed to `find_library()` will
+be passed to the `has_header()` method with the prefix removed.
+
+```meson
+libfoo = find_library('foo',
+  has_headers : ['foo.h', 'bar.h'],
+  header_prefix : '#include <baz.h>',
+  header_include_directories : include_directories('.'))
+```
+
+## NetCDF
+
+NetCDF support for C, C++ and Fortran is added via pkg-config.
+
+## added the Flang compiler
+[Flang](https://github.com/flang-compiler/flang/releases) Fortran
+compiler support was added.  As with other Fortran compilers, flang is
+specified using `FC=flang meson ..` or similar.
+
+## New `not_found_message` for dependency
+
+You can now specify a `not_found_message` that will be printed if the
+specified dependency was not found. The point is to convert constructs
+that look like this:
+
+```meson
+d = dependency('something', required: false)
+if not d.found()
+  message('Will not be able to do something.')
+endif
+```
+
+Into this:
+
+```meson
+d = dependency('something',
+  required: false,
+  not_found_message: 'Will not be able to do something.')
+```
+
+Or constructs like this:
+
+```meson
+d = dependency('something', required: false)
+if not d.found()
+  error('Install something by doing XYZ.')
+endif
+```
+
+into this:
+
+```meson
+d = dependency('something',
+  not_found_message: 'Install something by doing XYZ.')
+```
+
+Which works, because the default value of `required` is `true`.
+
+## Cuda support
+
+Compiling Cuda source code is now supported, though only with the
+Ninja backend. This has been tested only on Linux for now.
+
+Because NVidia's Cuda compiler does not produce `.d` dependency files,
+dependency tracking does not work.
+
+## `run_command` accepts `env` kwarg
+
+You can pass [`environment`](Reference-manual.html#environment-object)
+object to [`run_command`](Reference-manual.html#run-command), just
+like to `test`:
+
+```meson
+env = environment()
+env.set('FOO', 'bar')
+run_command('command', 'arg1', 'arg2', env: env)
+```
+
+## `extract_objects` accepts `File` arguments
+
+The `extract_objects` function now supports File objects to tell it
+what to extract. Previously, file paths could only be passed as strings.
+
+## Changed the JSON format of the introspection
+
+All paths used in the meson introspection JSON format are now absolute. This
+affects the `filename` key in the targets introspection and the output of
+`--buildsystem-files`.
+
+Furthermore, the `filename` and `install_filename` keys in the targets
+introspection are now lists of strings with identical length.
+
+The `--target-files` option is now deprecated, since the same information
+can be acquired from the `--tragets` introspection API.
+
+## Meson file rewriter
+
+This release adds the functionality to perform some basic modification
+on the `meson.build` files from the command line. The currently
+supported operations are:
+
+- For build targets:
+  - Add/Remove source files
+  - Add/Remove targets
+  - Modify a select set of kwargs
+  - Print some JSON information
+- For dependencies:
+  - Modify a select set of kwargs
+- For the project function:
+  - Modify a select set of kwargs
+  - Modify the default options list
+
+For more information see the rewriter documentation.
+
+## `introspect --scan-dependencies` can now be used to scan for dependencies used in a project
+
+It is now possible to run `meson introspect --scan-dependencies
+/path/to/meson.build` without a configured build directory to scan for
+dependencies.
+
+The output format is as follows:
+
+```json
+[
+  {
+    "name": "The name of the dependency",
+    "required": true,
+    "conditional": false,
+    "has_fallback": false
+  }
+]
+```
+
+The `required` keyword specifies whether the dependency is marked as required
+in the `meson.build` (all dependencies are required by default). The
+`conditional` key indicates whether the `dependency()` function was called
+inside a conditional block. In a real meson run these dependencies might not be
+used, thus they _may_ not be required, even if the `required` key is set. The
+`has_fallback` key just indicates whether a fallback was directly set in the
+`dependency()` function.
+
+## `introspect --targets` can now be used without configured build directory
+
+It is now possible to run `meson introspect --targets /path/to/meson.build`
+without a configured build directory.
+
+The generated output is similar to running the introspection with a build
+directory. However, there are some key differences:
+
+- The paths in `filename` now are _relative_ to the future build directory
+- The `install_filename` key is completely missing
+- There is only one entry in `target_sources`:
+  - With the language set to `unknown`
+  - Empty lists for `compiler` and `parameters` and `generated_sources`
+  - The `sources` list _should_ contain all sources of the target
+
+There is no guarantee that the sources list in `target_sources` is correct.
+There might be differences, due to internal limitations. It is also not
+guaranteed that all targets will be listed in the output. It might even be
+possible that targets are listed, which won't exist when meson is run normally.
+This can happen if a target is defined inside an if statement.
+Use this feature with care.
+
+## Added option to introspect multiple parameters at once
+
+Meson introspect can now print the results of multiple introspection
+commands in a single call. The results are then printed as a single JSON
+object.
+
+The format for a single command was not changed to keep backward
+compatibility.
+
+Furthermore the option `-a,--all`, `-i,--indent` and `-f,--force-object-output`
+were added to print all introspection information in one go, format the
+JSON output (the default is still compact JSON) and force use the new
+output format, even if only one introspection command was given.
+
+A complete introspection dump is also stored in the `meson-info`
+directory. This dump will be (re)generated each time meson updates the
+configuration of the build directory.
+
+Additionlly the format of `meson introspect target` was changed:
+
+  - New: the `sources` key. It stores the source files of a target and their compiler parameters.
+  - New: the `defined_in` key. It stores the meson file where a target is defined
+  - New: the `subproject` key. It stores the name of the subproject where a target is defined.
+  - Added new target types (`jar`, `shared module`).
+
+## meson configure can now print the default options of an unconfigured project
+
+With this release, it is also possible to get a list of all build options
+by invoking `meson configure` with the project source directory or
+the path to the root `meson.build`. In this case, meson will print the
+default values of all options.
+
+## HDF5
+
+HDF5 support is added via pkg-config.
+
+## Added the `meson-info.json` introspection file
+
+Meson now generates a `meson-info.json` file in the `meson-info` directory
+to provide introspection information about the latest meson run. This file
+is updated when the build configuration is changed and the build files are
+(re)generated.