# Installer fourmolu avec Homebrew, Nix

Consultez les chemins d'installation, exécutables, métadonnées et notes de sécurité de fourmolu pour les workflows d'agents IA.

## installation

```sh
sudo av install brew:fourmolu
```

Commandes d'installation supplémentaires:

### macOS

- Homebrew (100%):

```sh
brew install fourmolu
```

  Preuve: local Homebrew formula metadata

### Linux

- Nix (92%):

```sh
nix profile install nixpkgs#fourmolu
```

  Preuve: nixpkgs package indexes: pkgs/by-name/fo/fourmolu/package.nix from https://api.github.com/repos/NixOS/nixpkgs/git/trees/master?recursive=1

## Faits du paquet

- **Clé du paquet:** brew:fourmolu
- **Gestionnaire de paquets:** Homebrew
- **Page du gestionnaire de paquets:** <https://formulae.brew.sh/formula/fourmolu>
- **Version:** 0.20.0.0
- **Résumé source:** Formatter for Haskell source code
- **Page d'accueil:** <https://fourmolu.github.io/>
- **Dépôt:** <https://github.com/fourmolu/fourmolu>
- **Docs amont:** <https://fourmolu.github.io/>
- **Licence:** BSD-3-Clause
- **Archive source:** <https://hackage.haskell.org/package/fourmolu-0.20.0.0/fourmolu-0.20.0.0.tar.gz>
- **Dernière mise à jour:** 2026-07-22T05:23:32Z
- **Généré:** 2026-08-04T22:13:35+00:00

## exécutables

- fourmolu (cli)
- fourmolu (alias)

## Dépendances

- gmp

## Dépendances de compilation

- cabal-install
- ghc

## Bibliothèques fournies par macOS

- libffi

## Comportement d'installation

- hook post-installation: non défini
- Bouteille: disponible sur arm64_linux, arm64_sequoia, arm64_sonoma, arm64_tahoe, sonoma, x86_64_linux

## Version et fraîcheur

- page générée: 2026-08-04
- version du gestionnaire: 0.20.0.0
- gestionnaire mis à jour: 2026-07-22
- données locales: OK
- dépôt amont: https://fourmolu.github.io/
- info: Release/tag comparison is only available for GitHub repositories.
## Historique du projet et usages

Fourmolu is a formatter for Haskell source code. It is an Ormolu fork that keeps Ormolu's parser-driven, idempotent formatting goals while adding configurable style options through CLI flags and `fourmolu.yaml`.

### Historique du projet

The repository was created in 2020 and describes itself as a fork of Ormolu with upstream improvements continually merged. The official README frames the project around one key departure from Ormolu: replacing the no-configuration style rule with configurable parameters.

The changelog shows a pattern of adding Fourmolu-specific configuration while also importing upstream Ormolu changes, including parser updates, formatting fixes, and support for new GHC language features.

### Historique d'adoption

Fourmolu is adopted by Haskell projects that want automatic formatting but need policy knobs that Ormolu intentionally avoids. The README documents installation through GHCup, Cabal, Stack, release notes, editor integration through Haskell Language Server, and CI through the recommended `run-fourmolu` GitHub Action.

### Modes d'utilisation

Users run `fourmolu Module.hs` to print formatted output, `fourmolu -i` to rewrite files, or `fourmolu --mode check` in CI. Configuration can be written in `fourmolu.yaml`, discovered from parent directories and the XDG config directory, or passed as command-line options.

### Pourquoi les passionnés de paquets s'y intéressent

Fourmolu is a package-nerd case study in formatter governance. It forked an intentionally opinionated tool not to change the parser architecture, but to change the social contract around style configuration, while still tracking upstream Ormolu.

### Chronologie

- 2020: The public `fourmolu/fourmolu` repository was created.
- 2023: v0.13.x and v0.14.x releases continued the configurable formatter line.
- 2024: v0.16.x added explicit configuration-file selection and upstream parser updates.
- 2025: v0.19.0.0 added options such as `haddock-location-signature` and `if-style`.
- 2026: v0.20.0.0 made Fourmolu installable with GHCup and added more import-grouping and record-style configuration.

### Related projects

- Fourmolu is directly related to Ormolu, GHC, ghc-lib-parser, Cabal, Stack, GHCup, Haskell Language Server, Hackage, and the `run-fourmolu` GitHub Action.

### Sources

- <https://api.github.com/repos/fourmolu/fourmolu>
- <https://api.github.com/repos/fourmolu/fourmolu/releases>
- <https://fourmolu.github.io/>
- <https://fourmolu.github.io/changelog/>
- <https://fourmolu.github.io/config/>
- <https://github.com/fourmolu/fourmolu>
- <https://raw.githubusercontent.com/fourmolu/fourmolu/main/README.md>


## Notes de sécurité

narrow executable package without higher-risk signals.

- **Risque Geiger:** vert / faible
- narrow executable package without higher-risk signals


## Configuration and credential file locations

These source-backed paths show where this package keeps local settings or durable credentials. Automic Vault can use them as review targets for secret scanning, migration, and command approval.


## Configuration files

- Unix: fourmolu.yaml
## Détails de la base source

- **Source Database:** Homebrew formula API
- **Tap:** homebrew/core
- **Full Name:** fourmolu
- **Version Scheme:** 0
- **Revision:** 0
- **Head Version:** HEAD
- **Bottle Stable Root URL:** <https://ghcr.io/v2/homebrew/core>
- **Deprecated:** no
- **Disabled:** no
- **Keg Only:** no
- **URL Keys:** head, stable

## Autres enregistrements de gestionnaires de paquets

- Nix - fourmolu: normalized package name match | nixpkgs package indexes: pkgs/by-name/fo/fourmolu/package.nix from https://api.github.com/repos/NixOS/nixpkgs/git/trees/master?recursive=1


## Liens liés

- [Source-control packages](https://pkg.so/fr/source-control-tools/) - Belongs to a source-control command family.
- [Terminal utility packages](https://pkg.so/fr/terminal-utilities/) - Matched terminal and command-line workflow metadata.
- [Text processing packages](https://pkg.so/fr/text-processing-tools/) - Matched text, document, or structured-data processing metadata.
- [Developer build packages](https://pkg.so/fr/developer-build-tools/) - Matched build, compiler, generator, or developer workflow metadata.
- [cabal-install](https://pkg.so/fr/brew/cabal-install/) - Build dependency declared by Homebrew.
- [ghc](https://pkg.so/fr/brew/ghc/) - Build dependency declared by Homebrew.
- [scalariform](https://pkg.so/fr/brew/scalariform/) - Shares pkgdb curated category or tags: cli, developer-tools, formatter, source-code.
- [hindent](https://pkg.so/fr/brew/hindent/) - Shares pkgdb curated category or tags: cli, developer-tools, formatter, haskell, source-code.
- [swift-format](https://pkg.so/fr/brew/swift-format/) - Shares pkgdb curated category or tags: cli, developer-tools, formatter, source-code.
- [goimports](https://pkg.so/fr/brew/goimports/) - Shares pkgdb curated category or tags: cli, developer-tools, formatter.
- [ktfmt](https://pkg.so/fr/brew/ktfmt/) - Shares pkgdb curated category or tags: cli, developer-tools, formatter.
- [ormolu](https://pkg.so/fr/brew/ormolu/) - Shares pkgdb curated category or tags: cli, developer-tools, formatter, haskell.
- [haskell-language-server](https://pkg.so/fr/brew/haskell-language-server/) - Shares pkgdb curated category or tags: cli, developer-tools, haskell.
- [dfmt](https://pkg.so/fr/brew/dfmt/) - Shares pkgdb curated category or tags: cli, developer-tools, formatter, source-code.
- [cgrep](https://pkg.so/fr/brew/cgrep/) - Both packages touch the same language runtime or ecosystem. Shared terms: cli, code, developer, developer-tools, gmp.

## Combined YAML source

View the package source record on GitHub. [combined/fourmolu.yml](https://github.com/mxcl/pkgdb/blob/main/combined/fourmolu.yml)


## Sources

- pkg.so package database
- Geiger risk classifier
- package-page enrichment
- curated configuration and credential file locations
- curated package history
- package version freshness
- pkgdb category and tag curation
- package relationship graph
- external package-manager database matches
- cross-ecosystem install command graph