xynovim guide

Cargo workspaces, features and dependencies in Neovim

Adding a dependency, picking its features and starting a workspace are chores that usually mean a terminal, a browser tab for crates.io and a manual edit of Cargo.toml. This guide covers the commands of xynovim, a personal Neovim configuration for Rust, that do these inside the editor: new projects and workspaces, :CrateAdd with feature selection, :CrateFeatures, the code action that enables a missing derive feature, and the feature set that rust-analyzer and clippy share.

a new Cargo workspace in Neovim: the file tree with crates, the member and the root Cargo.toml — Recorded from the real configuration on the demo crate.

New projects and workspaces

Three dashboard entries and four commands create projects. They all run cargo underneath, asynchronously, and remove whatever they created if cargo fails.

Dashboard	Command	What it creates
`b`	`:RustNewBin [name]`	`cargo new --bin --vcs git`, then opens `src/main.rs`
`i`	`:RustNewLib [name]`	the same with `src/lib.rs`; a hyphenated name shows its Rust identifier
`w`	`:RustNewWorkspace [name]`	a workspace with a first member
	`:RustNewMember [name]`	adds a binary or library to the workspace of the current buffer

Cargo has no one-step workspace command, so xynovim builds it: a root Cargo.toml with [workspace], resolver = "3" (or "2" for editions before 2024), members = ["crates/*"], [workspace.package] and an empty [workspace.dependencies], and a first member under crates/ that inherits version.workspace and edition.workspace. The edition is whatever your installed cargo writes into a new project, read once per session, never hard-coded. The crates/* glob picks up later members without editing the manifest. :RustNewMember refuses outside a workspace with a members list and refuses a name that collides with an existing member.

the root Cargo.toml of a new workspace: workspace table, resolver and workspace.package — The root manifest of a workspace created from the dashboard.

The fourth dashboard entry, e, runs :EguiNew [name], which downloads the current eframe_template, personalises it and keeps your own Rust toolchain instead of the template's pin.

Adding a crate with its features

<leader>rA or :CrateAdd [query] searches crates.io and shows version, downloads and the features of the chosen release with their descriptions. You pick features and the target: the package that holds the file, --dev or --build, and workspace.dependencies entries are used when they exist. Then it runs cargo add. Writing a path such as uuid::Uuid::new_v4() for a crate that is not a dependency yet gives a hint and a code action, "Add crate uuid", that does the same and then offers the import.

the feature picker of the uuid crate with the v4 feature toggled on — The feature picker of `:CrateAdd`, here with `v4` toggled on.

Exploring and fixing features

:CrateFeatures [crate] is a feature explorer: which features are on or off, what each one unlocks, the default set, an "unused?" hint, and toggling in Cargo.toml.
<leader>rG, or the code action "Enable feature derive of serde", fixes cannot find derive macro Serialize: the feature is found in the crate's own source and Cargo.toml is edited.
<leader>rI or :ImportName imports a name with the candidates ranked and the reasons shown, and remembers your choice per project.

the error cannot find derive macro Serialize because the serde derive feature is off — The error that the enable-feature action repairs.

One feature set for the whole workspace

:RustContext chooses the Cargo features and the build target for a workspace, and applies them to rust-analyzer and bacon-ls together so the two diagnostic tiers cannot disagree. :RustTargets lists every binary, example, test and bench of the workspace, and :RustTools opens cargo-deny, audit, machete, bloat and build timings when those tools are installed.

After a dependency changes

Saving Cargo.toml or Cargo.lock from Neovim restarts bacon-ls 500 ms after the last save, and the statusline says deps resolving until rust-analyzer finishes reloading, so a red error in that window is understood as transient. A cargo add in a terminal gets the same treatment on the next focus event.

Limits

Project creation depends on cargo's own naming rules and on a network for crates.io and the egui template; the egui flow uses a cached copy offline.
The unknown-crate hint is deliberately conservative: a file with a glob import from a dependency gets no hint.
New Rust and egui project creation is not demonstrated on Windows or macOS.

Try it

Install the configuration, open the dashboard and press w to create a workspace, then use <leader>rA inside a member to add a crate.

Install

git clone https://github.com/xynorash/xynovim ~/.config/nvim   # or ln -s <checkout> ~/.config/nvim
~/.config/nvim/scripts/bootstrap.sh

xynovim is a personal project: the home page has the tour, the install details and the platform status.