elan-init を Homebrew, apt, Nix, scoop, winget, MacPorts でインストール

プロジェクトリンク

• ホームページ
• 上流ドキュメント
• パッケージマネージャページ

コマンドとエイリアス

• elan
• elan-init
• lake
• lean
• leanc
• leanchecker
• leanmake
• leanpkg

プロジェクトの歴史

The elan repository was created in April 2018 as Lean's answer to language-specific version managers. Its README explicitly describes the implementation as a fork of rustup, adapted from Rust's toolchain model to Lean's compiler, package manager, and release infrastructure.

The design followed Lean's project-local workflow: a repository can commit a `lean-toolchain` file, and elan will automatically select and download the required Lean version when `lean` or `lake` is invoked.

採用の歴史

elan became central to modern Lean usage because Lean projects often depend on precise compiler versions, especially around Lean 4 nightly and stable releases. The Lean reference manual documents elan as the standard way to manage installed toolchains, select defaults, and override versions per project.

Its package adoption is practical rather than flashy: package managers distribute `elan-init`, while the installed proxies expose Lean, Lake, and related tools under their usual command names.

使われ方

Typical usage starts with the `elan-init` installer, which installs into `~/.elan` by default and can update shell startup files. After installation, `elan show`, `elan default`, and project-local `lean-toolchain` files control which Lean version is active.

For package maintainers, elan matters because a single package can provide a family of executables while deferring the actual Lean compiler download until a project requests a specific toolchain.

パッケージ好きにとっての重要性

elan is a clean example of the rustup pattern spreading to another language ecosystem: a tiny manager package, shim executables, per-project version files, and lazy toolchain installation. That makes it especially interesting in package-manager databases because the package name `elan-init` is only the installer face of a larger language runtime workflow.

タイムライン

• 2018: GitHub repository created for the Lean toolchain manager.
• 2023: README examples show Lean 4 nightly toolchains selected by `lean-toolchain`.
• 2025: v4.0.0 released for the Lean 4 era.
• 2026: v4.2.x releases continue active maintenance.

Related projects

• elan is closely related to Lean, Lake, leanpkg, and rustup. Its model also resembles ghcup, pyenv, nvm, and other language version managers, but it is tightly integrated with Lean's official toolchain naming.

ソース

• https://github.com/leanprover/elan
• https://raw.githubusercontent.com/leanprover/elan/master/README.md
• https://lean-lang.org/doc/reference/latest/Build-Tools-and-Distribution/Managing-Toolchains-with-Elan
• https://api.github.com/repos/leanprover/elan
• https://api.github.com/repos/leanprover/elan/releases