astral-sh/uv · error

No packages found in workspace

Error message

No packages found in workspace

What it means

Raised on the `--all-packages` path when workspace discovery succeeded but workspace.packages() is empty — the discovered workspace root has no members at all (not even itself as a package). This is checked before filtering for buildable packages, so it indicates a structural workspace problem rather than missing build-system tables.

Source

Thrown at crates/uv/src/commands/build_frontend.rs:406

            package.root(),
        )))]
    } else if all_packages {
        if matches!(src, Source::File(_)) {
            return Err(anyhow::anyhow!(
                "Cannot specify `--all-packages` when building from a file"
            ));
        }

        let workspace = match workspace {
            Ok(ref workspace) => workspace,
            Err(err) => {
                return Err(err)
                    .context("`--all-packages` was provided, but no workspace was found");
            }
        };

        if workspace.packages().is_empty() {
            return Err(anyhow::anyhow!("No packages found in workspace"));
        }

        let packages: Vec<_> = workspace
            .packages()
            .values()
            .filter(|package| package.pyproject_toml().is_package(true))
            .map(|package| AnnotatedSource {
                source: Source::Directory(Cow::Borrowed(package.root())),
                package: Some(package.project().name.clone()),
            })
            .collect();

        if packages.is_empty() {
            let member = workspace.packages().values().next().unwrap();
            let name = &member.project().name;
            let pyproject_toml = member.root().join("pyproject.toml");
            return Err(anyhow::anyhow!(
                "Workspace does not contain any buildable packages. For example, to build `{}` with `{}`, add a `{}` to `{}`:\n```toml\n[build-system]\nrequires = [\"uv_build>={min_version},<{max_version}\"]\nbuild-backend = \"uv_build\"\n```",

View on GitHub (pinned to f1a42680ff)

Solutions

1. Add at least one package: create a pyproject.toml with [project] (+ [build-system]) in the root or a member directory.
2. Fix `tool.uv.workspace.members` globs so they match the actual package directories.
3. Loosen over-broad `tool.uv.workspace.exclude` patterns that remove every candidate.
4. Verify you are running from the intended workspace root (`--directory`/`--project`).

Example fix

# before: root pyproject.toml
[tool.uv.workspace]
members = ["crates/*"]   # crates/ does not exist
# after
[tool.uv.workspace]
members = ["packages/*"]  # matches packages/a, packages/b

# Rust: assert non-empty workspace before building all packages
let workspace = Workspace::discover(dir, &DiscoveryOptions::default(), cache, ws_cache).await?;
anyhow::ensure!(
    !workspace.packages().is_empty(),
    "workspace at {} has no members; check tool.uv.workspace.members",
    dir.display()
);

When it happens

Trigger: `uv build --all-packages` in a directory whose pyproject.toml declares a workspace but lists no buildable root package and no members; malformed tool.uv.workspace.members/exclude patterns matching nothing; running in an empty scaffold project.

Common situations: Newly initialized workspace where packages were planned but not added; globs in members (e.g., 'crates/*') that match no directories because the tree layout changed; exclude patterns accidentally filtering everything.

Related errors

• Package `{package}` not found in workspace
• Workspace does not contain any buildable packages. For examp
• pip-compile's `--config` is unsupported (uv does not use a c
• pip-sync's `--config` is unsupported (uv does not use a conf
• Multiple `pylock.toml` files specified: `{}` vs. `{}`

AI-assisted analysis of astral-sh/uv@f1a42680ff (2026-08-16). Data as JSON: /api/errors/7cd3330eb516dd06. Report an issue: GitHub.