Manifests — Rune docs

Rune reads Cargo's manifest format from either file, so a project can be plain Cargo, Rune-only, or both:

The directory has	The manifest is
`Cargo.toml`	`Cargo.toml` (as always)
`Rune.toml` with a `[package]` or `[workspace]` table (and no `Cargo.toml`)	`Rune.toml` — a Rune-only project
`Rune.toml` with only settings (`[build]`, `[cas]`, …) beside a `Cargo.toml`	`Cargo.toml`; the `Rune.toml` is just settings, exactly as before
both, and both have `[package]`/`[workspace]`	`Rune.toml` (`rune doctor` warns, because plain `cargo` would read the other)

bash

rune new my-app --manifest rune       # creates Rune.toml, no Cargo.toml
rune init --manifest rune             # in an existing directory; keeps a settings-only Rune.toml's settings
rune run / build / test / add / remove / metadata / locate-project …   # all work on either

The contents are the same [package], [dependencies], [workspace], [features], [profile.*], [[bin]], … as in Cargo. Everything that finds a manifest — workspace roots and members, --manifest-path (a file, or a directory), path dependencies, git dependencies, [patch], rune add/remove (which edit the file they found), rune metadata / locate-project / --message-format json — asks one place, so they cannot disagree. A workspace may mix the two, and a path or git dependency may be Rune.toml-only. Registry crates are always Cargo.toml (that is what cargo publish produces).

A Rune.toml manifest can also hold Rune's own settings tables next to the manifest tables; rune config set build.jobs 4 writes into the same file and keeps the rest. One name collides: [test] (settings) and [[test]] (test targets). A [test] table is read as settings; if the file has [[test]] targets, rune config set test.… refuses and points at --global or the RUNE_TEST_… environment variable.

What you give up without a Cargo.toml: plain cargo, rust-analyzer setups and other tools that look for one only understand it. The lockfile stays Cargo.lock (Cargo's format) either way. The file name is not part of any cache key, so the Cargo.toml and Rune.toml versions of one project share compiled artifacts. Verified on Rune's own workspace (11 manifests) with every Cargo.toml renamed: 182 units build, 0 compiled after wiping target, all tests pass, and Cargo.lock is identical.