xai-org/grok-build · error · io::Error

compressed index requires 'compression' feature

Error message

compressed index requires 'compression' feature

What it means

The index file can be stored zstd-compressed, but decompression requires the optional 'compression' cargo feature. When the binary was built without that feature and read_from encounters a compressed index, it cannot decode it and returns io::ErrorKind::InvalidData, "compressed index requires 'compression' feature".

Source

Thrown at crates/codegen/xai-grok-workspace/src/file_system/index.rs:935

        r.read_exact(&mut buf2)?;
        let flags = u16::from_le_bytes(buf2);

        // Handle compression
        if flags & FLAG_COMPRESSED != 0 {
            #[cfg(feature = "compression")]
            {
                r.read_exact(&mut buf4)?;
                let _n_segs = u32::from_le_bytes(buf4);
                r.read_exact(&mut buf4)?;
                let _n_entries = u32::from_le_bytes(buf4);

                let mut compressed = Vec::new();
                r.read_to_end(&mut compressed)?;
                let decompressed = zstd::stream::decode_all(io::Cursor::new(compressed))?;
                return Self::from_bytes(&decompressed);
            }
            #[cfg(not(feature = "compression"))]
            return Err(io::Error::new(
                io::ErrorKind::InvalidData,
                "compressed index requires 'compression' feature",
            ));
        }

        r.read_exact(&mut buf4)?;
        let n_segs = u32::from_le_bytes(buf4) as usize;
        r.read_exact(&mut buf4)?;
        let n_entries = u32::from_le_bytes(buf4) as usize;

        // Read segment table (supports non-UTF-8 bytes)
        let mut interner = StringInterner::with_capacity(n_segs * 20, n_segs);
        let mut seg_id_map = Vec::with_capacity(n_segs);
        for _ in 0..n_segs {
            r.read_exact(&mut buf2)?;
            let len = u16::from_le_bytes(buf2) as usize;
            let mut seg_buf = vec![0u8; len];
            r.read_exact(&mut seg_buf)?;

View on GitHub (pinned to bc7f02eddd)

Solutions

1. Enable the feature: add xai-grok-workspace = { version = "...", features = ["compression"] } in Cargo.toml and rebuild.
2. Regenerate the index uncompressed by rewriting it with a build that has compression disabled (write path will skip compression).
3. Align feature flags across your workspace so every consumer enables the same 'compression' setting.
4. Run `cargo tree -f "{p} {f}"` to confirm which build actually has the feature and fix feature unification.

Example fix

// before
xai-grok-workspace = "0.4"
// after
xai-grok-workspace = { version = "0.4", features = ["compression"] }

fn compressed_index_supported() -> bool {
    cfg!(feature = "compression")
}
// inspect header/flag or just ensure the feature is on before reading

match Index::read_from(&mut file) {
    Ok(i) => i,
    Err(e) if e.to_string().contains("requires 'compression' feature") => {
        // rebuild an uncompressed index instead of failing
        Index::rebuild(&workspace_root)?
    }
    Err(e) => return Err(e.into()),
}

When it happens

Trigger: Reading an index file that was written in compressed form while the crate was compiled without the 'compression' feature (e.g. default build, or a dependency pinned the feature off).

Common situations: Index was produced by a build with the compression feature enabled, then consumed by a build without it; a dependency resolver (feature unification) disabled the feature; switching from a full build to a minimal build in CI.

Related errors

• failed to build request: {e}
• failed to serialize MCP server {name}: {e}
• failed to serialize MCP server config: {e}
• failed to parse {}: {e}
• -32603

AI-assisted analysis of xai-org/grok-build@bc7f02eddd (2026-08-31). Data as JSON: /api/errors/7e05abd53bf4bfaf. Report an issue: GitHub.