Packages on the fly

When no module or toolchain gives you a tool, take it straight from Nixpkgs, the package collection of NixOS. You run these commands inside the VM, for your own account, and none of them needs sudo.

Try a tool without installing it

VM

nix shell nixpkgs#openssl --command openssl version

This runs one command with the tool. Without --command, nix shell nixpkgs#openssl opens a shell with the tool on your PATH; exit drops it again.

Install a package

VM

nix profile add nixpkgs#ripgrep

The package goes into your profile and stays there until you remove it. nixpkgs here is the VM's own NixOS release: the same package set that the system and the modules use. A tool you add shares their libraries, and nothing is downloaded twice.

List and remove packages

Task	Command
List what you installed	nix profile list
Remove a package	nix profile remove ripgrep
Free the disk space of removed packages	nix profile wipe-history

Older versions of your profile keep removed packages on disk until you run nix profile wipe-history. lmx never deletes them when it cleans up the disk; see Make room on the disk.

Find a package name

Search search.nixos.org in the channel of your VM's NixOS release. nixos-version shows it, such as 26.05.

Profile or limanix.toml

Your profile belongs to this VM. A tool that every VM of yours should have belongs in limanix.toml, where it is part of the system that the VM is built from:

limanix.toml

[nixos]
packages = ["tree"]

Use	When
nix shell	You need a tool once
nix profile add	You want to keep a tool for yourself in this VM
packages in limanix.toml	Every VM made from the file should have it; limanix update applies it and restarts the VM
[toolchains] or a module	A language, or a tool that needs more than its package, such as a service or the language server for the editor

Modules and packages explains the packages list, and Toolchains the languages.