transact-rs/sqlx · error

Could not fetch metadata

Error message

Could not fetch metadata

What it means

sqlx's `query!` macros run `cargo metadata --format-version=1 --no-deps` in the crate's manifest directory to locate the workspace root (for resolving `.env` and config). This `.expect()` panics if the `cargo metadata` command fails to execute at all (non-zero exit / cannot spawn).

Source

Thrown at sqlx-macros-core/src/query/metadata.rs:45

        self.env.get_or_try_init(|builder| {
            load_env(&self.manifest_dir, &workspace_root, &self.config, builder)
        })
    }

    pub fn workspace_root(&self) -> PathBuf {
        let mut root = self.workspace_root.lock().unwrap();
        if root.is_none() {
            use serde::Deserialize;
            use std::process::Command;

            let cargo = crate::env("CARGO").unwrap();

            let output = Command::new(cargo)
                .args(["metadata", "--format-version=1", "--no-deps"])
                .current_dir(&self.manifest_dir)
                .env_remove("__CARGO_FIX_PLZ")
                .output()
                .expect("Could not fetch metadata");

            #[derive(Deserialize)]
            struct CargoMetadata {
                workspace_root: PathBuf,
            }

            let metadata: CargoMetadata =
                serde_json::from_slice(&output.stdout).expect("Invalid `cargo metadata` output");

            *root = Some(metadata.workspace_root);
        }
        root.clone().unwrap()
    }
}

pub fn try_for_crate() -> crate::Result<Arc<Metadata>> {
    /// The `MtimeCache` in this type covers the config itself,
    /// any changes to which will indirectly invalidate the loaded env vars as well.

View on GitHub (pinned to 03af8bcc57)

Solutions

1. Run `cargo metadata --format-version=1 --no-deps` manually in the crate dir to see the real error; fix the reported Cargo.toml/workspace problem.
2. Ensure the build is invoked through cargo so cargo is on PATH and CARGO_MANIFEST_DIR points at a valid crate.
3. Fix or regenerate Cargo.lock / Cargo.toml if the manifest is corrupt.
4. Clear stale target dir / `cargo clean` and rebuild.

// Pre-check before building with sqlx macros:
use std::process::Command;
let out = Command::new("cargo").args(["metadata", "--format-version=1", "--no-deps"]).output().unwrap();
assert!(out.status.success(), "cargo metadata failed: {}", String::from_utf8_lossy(&out.stderr));

When it happens

Trigger: Compiling a crate with `#[sqlx::test]`/`query!` macros while `cargo metadata` cannot run: cargo not on PATH (non-cargo build tool), corrupted workspace/manifest, or the command failing inside the manifest directory.

Common situations: Building with rust-analyzer or an IDE toolchain where cargo is unavailable or the working dir is wrong; broken Cargo.toml causing `cargo metadata` to exit non-zero; running builds from a directory where the manifest is missing; sandboxed CI denying process spawn.

Related errors

• Invalid `cargo metadata` output
• downcast to wrong DatabaseError type; original error: {self}
• downcast to wrong DatabaseError type; original error: {e}
• invalid column index: {}
• unimplemented!()

AI-assisted analysis of transact-rs/sqlx@03af8bcc57 (2026-09-03). Data as JSON: /api/errors/e5038004613a0f2c. Report an issue: GitHub.