Provided by: muon-meson_0.4.0-1_amd64 
NAME
muon - a meson-compatible build system
SYNOPSIS
muon [-vh] [-C <chdir>] <command> [<args>]
muon setup [-D[subproject:]option=value...] build
cd build
<invoke backend build tool>
muon test [options]
muon install [options]
DESCRIPTION
muon interprets source files written in the meson dsl and produces buildfiles for a backend.
When building meson projects with muon, you typically first start by running the setup command in the
project root. This will create buildfiles for the backend in the build dir you specify. You then invoke
the backend, e.g.
ninja -C <build dir>
If the project defines tests, you may run them with the test subcommand, and finally install the project
with the install subcommand.
OPTIONS
• -v - enable verbose output
• -C <path> - chdir to path before executing a command
• -h - print a help message
COMMANDS
muon requires a command.
All commands accept a -h option which prints a brief summary of their usage.
analyze
muon analyze [command]
Run a static analyzer on the current project.
OPTIONS:
• -l - optimize output for editor linter plugins. For example, a diagnostic is added for the
subdir() callsite, so that the editor can highlight subdirs with errors in them.
• -q - only report errors
• -O <path> - read project file with matching path from stdin. This is useful for editor linter
plugins that run as you type on files that aren't saved to disk.
• -i <path> - analyze the single file path in internal mode. This is useful for catching bugs in
scripts that will be evaluated with muon internal eval.
• -W [no-]<diagnostic> - enable or disable a particular diagnostic, e.g. unused-variable.
• -W list - list available diagnostics.
• -W error - turn all warnings into errors.
COMMANDS:
• trace - print a tree of all meson source files that are evaluated
• define <var> - print the location of the definition of var
fmt
muon fmt [-i] [-q] [-l] [-c <muon_fmt.ini>] <file>[ <file>[...]]
Format a source file.
OPTIONS:
• -q - exit with 1 if files would be modified by muon fmt
• -l - like -q but also print failing filenames
• -i - format files in-place
• -c <muon_fmt.ini> - read configuration from muon_fmt.ini
• -e - try to read configuration from .editorconfig. Only indentation related settings are
recognized.
CONFIGURATION OPTIONS
┌──────────────────────────┬────────────┬─────────┬────────────────────────┐
│ key │ type │ default │ description │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ max_line_len │ int │ 80 │ The maximum length of │
│ │ │ │ lines before they are │
│ │ │ │ split │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ indent_style │ space|tab │ space │ Wether to use spaces │
│ │ │ │ or tabs for │
│ │ │ │ indentation │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ indent_size │ int │ 4 │ For indent_style = │
│ │ │ │ space, the number of │
│ │ │ │ spaces to indent by │
│ │ │ │ per level │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ insert_final_newline │ bool │ true │ Whether or not to │
│ │ │ │ insert a trailing │
│ │ │ │ newline at the end of │
│ │ │ │ the file │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ end_of_line │ lf|crlf|cr │ <unset> │ The type of line │
│ │ │ │ ending to use. If │
│ │ │ │ this value is not set │
│ │ │ │ then the line ending │
│ │ │ │ of the first line in │
│ │ │ │ the source file will │
│ │ │ │ be used. │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ space_array │ bool │ false │ Whether to include │
│ │ │ │ spaces around array │
│ │ │ │ elements (ex. [1] vs [ │
│ │ │ │ 1 ]) │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ kwargs_force_multiline │ bool │ false │ Make every dictionary │
│ │ │ │ literal and function │
│ │ │ │ call with kwargs │
│ │ │ │ expand into multiple │
│ │ │ │ lines. │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ wide_colon │ bool │ false │ Whether to put a space │
│ │ │ │ before the colon │
│ │ │ │ operator (ex. `key : │
│ │ │ │ val`) │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ no_single_comma_function │ bool │ false │ Don't add a trailing │
│ │ │ │ comma to multi-line │
│ │ │ │ function calls with │
│ │ │ │ only one argument. │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ sort_files │ bool │ true │ Whether to sort the │
│ │ │ │ arguments of files() │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ group_arg_value │ bool │ true │ Whether to group │
│ │ │ │ strings in array │
│ │ │ │ literals such that │
│ │ │ │ command line arguments │
│ │ │ │ that take a value │
│ │ │ │ remain on the same │
│ │ │ │ line as the value. │
│ │ │ │ The heuristic used is │
│ │ │ │ that if a string │
│ │ │ │ starts with `-` and │
│ │ │ │ the next string does │
│ │ │ │ not, put both strings │
│ │ │ │ on the same line │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ simplify_string_literals │ bool │ false │ Whether to │
│ │ │ │ automatically convert │
│ │ │ │ multiline string │
│ │ │ │ literals without │
│ │ │ │ newlines, as well as │
│ │ │ │ f-strings without │
│ │ │ │ formatting into │
│ │ │ │ single-quoted string │
│ │ │ │ literals. │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ indent_before_comments │ str │ ' ' │ The indent to put │
│ │ │ │ before trailing │
│ │ │ │ comments │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ sticky_parens │ bool │ false │ Controls whether │
│ │ │ │ parenthesis used for │
│ │ │ │ grouping are stuck to │
│ │ │ │ what they enclose or │
│ │ │ │ are exploded out to be │
│ │ │ │ on their own lines. │
├──────────────────────────┼────────────┼─────────┼────────────────────────┤
│ continuation_indent │ bool │ false │ Controls whether a │
│ │ │ │ multiline conditional │
│ │ │ │ in an if statement │
│ │ │ │ gets an extra indent. │
└──────────────────────────┴────────────┴─────────┴────────────────────────┘
install
muon install [-n]
Installs the project. The DESTDIR environment variable is respected and will prefix all installation
directories if it is present.
OPTIONS:
• -n - dry run
• -d <destdir> - set destdir
internal
muon internal <command> [<args>]
Internal contains several subcommands used by muon internally. These commands are subject to change
at any time and should not be relied upon. Not all internal commands are documented.
COMMANDS:
• eval - evaluate a source file
• exe - execute a command
• repl - start a meson dsl repl
• dump_funcs - output all supported functions and arguments
internal check
muon internal check [-p|-d] [-m<x|f>] <filename>
Check if filename parses.
OPTIONS:
• -p - print the parsed ast
• -d - print the dissasembly
• -m <mode> - set the compilation mode. `f` parses for formatting, `x` compiles for the extended
language (e.g. user-defined functions)
internal eval
muon internal eval [-e] [-s] <filename> [<args>]
Evaluate a source file. The interpreter environment is substantially different from the typical
environment during setup. Build related functions are unavailable, as well as many other functions
including subdir. Additionally, the variable argv is defined as an array containing the commandline
starting at <filename>.
OPTIONS:
• -e - lookup <filename> as an embedded script
• -s - disable functions that are unsafe to be called at random, particularly `run_command()`. The
motivation for this flag is so that automated fuzz testing can be used without accidentally
executing something like `run_command('rm', '-rf', '/')`.
internal exe
muon internal exe [-f <input file>] [-c <output file>] [-e <env.dat>] [-a <args.dat>] [-R <file>] [--
<cmd> [<args>]]
Execute <cmd> with arguments <args>.
OPTIONS:
• -f <input file> - pass input file as stdin to <cmd>
• -c <output file> - capture stdout of <cmd> and write it to output file
• -e <env.dat> - read and set environment variables from env.dat
• -a <args.dat> - read and set command from args.dat
• -R <file> - remove file if it exists before executing the command
internal repl
muon internal repl
Start a meson dsl repl. The functions available are limited as with internal eval.
internal summary
muon internal summary
Print a previously configured project's summary.
internal dump_funcs
muon internal dump_funcs
Print all supported functions, methods, and module functions with their arguments, argument types,
and return types to stdout. This subcommand is mainly useful for generating
https://muon.build/status.html.
meson
[muon] meson ...
A compatibility layer that attempts to translate all flags and operands from meson cli syntax to muon
cli syntax. For example, the following two commands:
muon meson setup build --werror --prefix=/
muon meson test -C build --list
Would be translated into the following two muon versions respectively:
muon setup -Dwerror=true -Dprefix=/ build
muon -C build test -l
This compatibility layer is also enabled when muon's executable is named meson.
For a more detailed usage information you can use the following two commands:
muon meson -h
muon meson <subcommand> -h
NOTE: This is a best-effort translation and does not guarantee or imply full cli compatibility. Many
unimplemented flags are ignored and attempting to use an unsupported subcommands will result in an
error.
options
muon options [-a] [-m]
Lists available project options and defaults. This command may either be run from the project root
or from a build directory. Running this command from a build directory highlights configured option
values in the output, whereas running it from the project root causes the default value for each
option to be highlighted.
OPTIONS:
• -a - Include builtin global and per-project options in the output.
• -m - Only display option values that have been modified.
samu
muon samu [<args>]
Executes an embedded copy of samu(1). This command requires that muon was compiled with samu
enabled.
setup
muon setup [-D[subproject:]option=value...] <build dir>
Interpret all source files and generate buildfiles in build dir.
OPTIONS:
• -D [subproject:]option=value - Set build options. Options are either built in or project-
defined. Subproject options can be specified by prepending the subproject's name and a colon to
the option. This option may be specified multiple times.
subprojects
muon subprojects
Run various commands over all subprojects. Only subprojects with .wrap files are supported. Most
commands accept a list of projects as trailing arguments.
OPTIONS:
• -d <directory> - manually specify subprojects directory. By default muon will evaluate the
current project's project() call to determine the value for subproject_dir.
COMMANDS:
• check-wrap - check if a wrap file is valid
• update - update subprojects with .wrap files
• list - list subprojects with .wrap files and their status
• clean - clean wrap-git subprojects
test
muon test [-b] [-d <display mode>] [-o <output>] [-e <setup>] [-f] [-j <jobs>] [-l] [-R] [-s <suite>]
[-S] [-v [-v]] [<test> [<test>[...]]
Execute tests defined in source files.
The default is to execute all tests, but you can also specify which tests to execute on the command
line.
<test> should consist of an optional project name, followed by a colon and then a test name. Either
may be omitted. For example,
"test name" and ":test name" will match all tests named 'test name' in any project.
"proj:test name" will match all tests named 'test name' in the project 'proj'.
"proj:" will match all tests in the project 'proj'.
Additionally, the test name may be a glob expression. For example,
"proj:long*" will match all tests with names starting with 'long' in the project 'proj'.
OPTIONS:
• -b - run benchmarks instead of tests
• -d <display mode> - Control test progress output. display mode can be one of auto, dots, or bar.
dots prints a '.' for success and 'E' for error, bar prints a progress bar with an error count.
The default mode, auto, selects bar if the output device is a terminal or dots otherwise.
• -o <output mode> - Control test results output. term prints failures and output to the terminal,
html generates a single-page html report, and json outputs test information to a json file.
• -e <setup> - Use test setup setup.
• -f - Fail fast. exit after first test failure is encountered.
• -j - Set the number of jobs used when running tests.
• -l - List tests that would be run with the current setup, suites, etc. The format of the output
is <project name>:<list of suites> - <test_name>.
• -R - No rebuild. Disable automatic build system invocation prior to running tests.
• -s <suite> - Only run tests in suite suite. This option may be specified multiple times.
• -S - print a summary of test results, including the duration of each test
• -v - Increase verbosity. When passed once, print test results as they are completed. When
passed twice, the stdout/stderr of tests is not captured.
version
muon version
Print out version information as well as enabled features.
EXTENSIONS
muon provides some extra functions that may be called within source files. They are documented below.
• dbg() - Begin an interactive debugger.
• p(value) - Print any value's internal representation. For example, `p('hello')` prints `'hello'`.
SEE ALSO
meson.build(5) meson-reference(3) meson(1)
AUTHORS
Maintained by Stone Tickle <lattis@mochiro.moe>, who is assisted by other open source contributors. For
more information about muon development, see <https://sr.ht/~lattis/muon>.
2025-03-21 muon(1)