jdx/mise · error · eyre::Report

cached rustc output failed digest verification: {}

Error message

cached rustc output failed digest verification: {}

What it means

Before restoring a cached output file, the wrapper materializes the blob (reflink/copy) into a temp file and re-hashes it; the digest must match the node's recorded digest. A mismatch means the stored bytes degraded — corruption, truncation, or a bad copy — and the wrapper refuses to install wrong build artifacts (src/cache/rustc.rs:389).

Source

Thrown at src/cache/rustc.rs:389

}

fn stage_cached_output(
    directory: &Path,
    index: usize,
    source: &Path,
    node: &CacheFileNode,
) -> Result<tempfile::TempPath> {
    let temporary = directory.join(format!("output-{index}"));
    reflink_copy::reflink_or_copy(source, &temporary)
        .wrap_err_with(|| format!("failed to materialize cached rustc output {}", node.name))?;
    let temporary = tempfile::TempPath::try_from_path(temporary)?;
    make_owner_writable(&temporary)?;
    std::fs::OpenOptions::new()
        .write(true)
        .open(&temporary)?
        .sync_all()?;
    if !node.digest.matches_file(&temporary)? {
        bail!(
            "cached rustc output failed digest verification: {}",
            node.name
        );
    }
    apply_file_mode(&temporary, node.mode)?;
    Ok(temporary)
}

fn cached_matches(cached: &CachedCompilation, output: &Output) -> bool {
    output.status.success()
        && cached.stdout == output.stdout
        && cached.stderr == output.stderr
        && cached.outputs.iter().all(|expected| {
            std::fs::metadata(&expected.path).is_ok_and(|metadata| {
                file_mode(&metadata) == expected.mode
                    && expected
                        .digest
                        .matches_file(&expected.path)

View on GitHub (pinned to 9dcfcaa0dc)

Solutions

1. Delete the corrupted blob/cache store and rebuild so outputs are re-recorded
2. Check disk space and filesystem health if multiple outputs fail verification
3. If using reflink on an unusual FS, disable the rustc cache or copy the store fully before use

# Digest failure => corrupted blob: delete store, rebuild uncached
if grep -q 'failed digest verification' build.log; then
  rm -rf "$MISE_CACHE_STAGING_DIR"; cargo build
fi

When it happens

Trigger: Bit rot or truncated writes in the cache blob store; reflink/copy silently producing wrong bytes on an exotic filesystem; tampered or partially synced cache directory (rsync/interrupted disk full).

Common situations: Shared/network caches copied without full sync; disk-full during an earlier record; filesystems with buggy reflink support.

Related errors

• cached rustc action result has an invalid identity
• cached rustc action descriptor does not match the invocation
• cached rustc metadata is unsupported
• remote cache blob failed digest verification
• cache agent did not return an action prediction response

AI-assisted analysis of jdx/mise@9dcfcaa0dc (2026-08-17). Data as JSON: /api/errors/7c7d2cda555d2869. Report an issue: GitHub.