# elan

**Repository Path**: stchai/elan

## Basic Information

- **Project Name**: elan
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-06-07
- **Last Updated**: 2024-06-14

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# elan: Lean version manager

*elan* is a small tool for managing your installations of the [Lean theorem prover](https://leanprover.github.io). It places `lean` and `leanpkg` binaries in your `PATH` that automatically select and, if necessary, download the Lean version described in the `lean_version` field of your project's `leanpkg.toml`.
You can also install, select, run, and uninstall Lean versions manually using the commands of the `elan` executable.

```bash
~/my/package $ cat leanpkg.toml | grep lean_version
lean_version = "nightly-2018-04-10"
~/my/package $ leanpkg -v
info: downloading component 'lean'
 14.6 MiB /  14.6 MiB (100 %)   2.2 MiB/s ETA:   0 s
info: installing component 'lean'
Lean package manager, version nightly-2018-04-10
[...]
~/my/package $ elan show
installed toolchains
--------------------

stable
nightly-2018-04-06
nightly-2018-04-10
master

active toolchain
----------------

nightly-2018-04-10 (overridden by '/home/me/my/package/leanpkg.toml')
Lean (version 3.3.1, nightly-2018-04-10, commit d36b859c6579, Release)
```

# Installation

## Manual Installation

**Linux/macOS/Cygwin/MSYS2/git bash/...**: run the following command in a terminal:

```bash
curl https://raw.githubusercontent.com/leanprover/elan/master/elan-init.sh -sSf | sh
```

Alternatively, on **any supported platform**: Grab the [latest release](https://github.com/leanprover/elan/releases/latest) for your platform, unpack it, and run the contained installation program.

The installation will tell you where it will install elan to (`~/.elan` by default), and also ask you about editing your shell config to extend `PATH`. elan can be uninstalled via `elan self uninstall`, which should revert these changes.

## Homebrew

```bash
$ brew install elan
```

## Nix

```bash
$ nix-env -iA nixpkgs.elan
```

# Prerequisites

On some systems, `lean`/`leanpkg` will not work out of the box even if installed through elan:

* You'll need [git](https://git-scm.com/download) to download dependencies through `leanpkg`.
* macOS: Install [Homebrew](https://brew.sh/), then run `brew install gmp coreutils`.
  (`gmp` is required by `lean`, `coreutils` is required by `leanpkg`)

# Implementation

*elan* is basically a fork of [rustup](https://github.com/rust-lang-nursery/rustup.rs). Apart from new features and adaptions to the Lean infrastructure, these are the basic changes to the original code:

* Replaced every mention of `rustup` with `elan`, `cargo` with `leanpkg`, and `rust(c)` with `lean`
* Removed Windows installer... for now?
* Merged `CARGO_HOME` and `RUSTUP_HOME`
* Removed options to configure host triple