Languages

Each toolchain you choose in the [toolchains] table of limanix.toml installs a language with its build tools and its language server. This page shows how to use them inside the VM. To choose a language or its version, see Toolchains.

See what a toolchain installed

VM

lmx help go

The card shows the installed version, the commands on your PATH and common tasks. The topics are go, rust, python and nodejs.

Toolchain	Installs
Go	Go, the gopls language server, the Delve debugger and GCC for cgo
Rust	rustup with Cargo, rustc, rustfmt, Clippy and rust-analyzer, plus GCC, pkg-config and GDB
Python	Python with venv, virtualenv and the Pyright language server
Node.js	Node.js with npm and npx, and the TypeScript language server

Go

Run these from a directory that contains go.mod:

VM

go build ./...
go test ./...
go test -race ./...

GCC enables cgo and the race detector. The Delve debugger runs as dlv.

When a project's go.mod or go.work requires a newer Go, Go can download that toolchain and run it instead. To use only the installed Go, set GOTOOLCHAIN in limanix.toml and apply it with limanix update; a project that requires a newer Go then fails to build:

limanix.toml

[env]
GOTOOLCHAIN = "local"

Rust

Rust comes from rustup. When the VM starts after you choose or change the toolchain in limanix.toml, it downloads that toolchain, which needs network access. Until the download finishes, Cargo reports that no default toolchain is configured. Follow it with:

VM

systemctl --user status rust-toolchain

A failed download is tried again; systemctl --user restart rust-toolchain starts it at once. Then, from a directory that contains Cargo.toml:

VM

cargo build
cargo test
cargo fmt
cargo clippy

Task	Command
Show the toolchain in use	rustup show
Debug a program	rust-gdb
List or remove toolchains	rustup toolchain list, rustup toolchain uninstall

A channel does not move on its own: rustup update fetches its newest release. A default you set with rustup default stays until the value in limanix.toml changes. A project selects its own toolchain with a rust-toolchain.toml file; rustup installs it on first use. Toolchains in ~/.rustup and crates in ~/.cargo stay across VM updates. Commands from cargo install go to ~/.cargo/bin, which comes first on your PATH.

Python

Create a virtual environment in the project directory, activate it and install the project's dependencies:

VM

python -m venv .venv
source .venv/bin/activate
python -m pip install -r requirements.txt

The environment includes pip, and virtualenv .venv creates an equivalent one. Run deactivate to leave it. A virtual environment keeps the interpreter that created it: create it again after you change the Python version.

Node.js

From a directory that contains package.json:

VM

npm install
npm run build

npm install installs the project's dependencies, and npm run build runs its build script. Packages that build native addons with node-gyp also need Python, make and a C/C++ compiler, which the toolchain does not install.

Language servers in AstroNvim

AstroNvim, the editor of the terminal preset, turns on the language server of each toolchain you choose:

Toolchain	Language server	Good to know
Go	gopls
Rust	rust-analyzer	rustup runs the rust-analyzer of the project's toolchain, which matches the compiler
Python	Pyright	When it cannot find the project's dependencies, configure the environment in pyrightconfig.json or under [tool.pyright] in pyproject.toml
Node.js	typescript-language-server	Uses the project's own TypeScript when the project configures one

Open the project at its path in the VM, such as /workspace: the language servers then see its Linux dependencies. The Tree-sitter parsers for these languages come with the toolchains; add one for another language with :TSInstall LANGUAGE, which needs network access.

A language server on your PATH alone does not start in the editor. To turn on another one, such as a server from a project environment, add it to the servers option of AstroLSP in your Neovim configuration. With editor = "neovim", plain Neovim starts no language server until you configure its LSP client.

Native libraries

GCC comes with the Go and Rust toolchains, and Rust also has pkg-config. Code that links to a C library still needs that library and its headers: a Go package with cgo, a crate such as openssl-sys, a Python package with a native extension or a Node.js native addon. Python and Node.js packages that compile code also need build tools, and a virtual environment does not provide system libraries. Add what a project needs with a module of your own; see Your own modules.