astrid-runtime/astrid · error

read projected file {}: {error}

Error message

read projected file {}: {error}

What it means

Thrown when `read_to_end` fails while reading the contents of a projected file in `read_projection_file_nofollow`. The file was successfully opened (via open_projection_file_nofollow) but the actual read IO failed; the path is included in the message.

Source

Thrown at crates/astrid-kernel/src/lib.rs:1681

    }

    #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
    fn read_projection_file_nofollow(path: &Path) -> anyhow::Result<Vec<u8>> {
        use std::io::Read as _;

        let metadata = std::fs::symlink_metadata(path).map_err(|error| {
            anyhow::anyhow!("inspect projected file {}: {error}", path.display())
        })?;
        if metadata.file_type().is_symlink() || !metadata.is_file() {
            anyhow::bail!(
                "projected path is redirected or not a regular file: {}",
                path.display()
            );
        }
        let mut file = open_projection_file_nofollow(path)?;
        let mut bytes = Vec::new();
        file.read_to_end(&mut bytes)
            .map_err(|error| anyhow::anyhow!("read projected file {}: {error}", path.display()))?;
        if file.metadata()?.len() != metadata.len() || bytes.len() as u64 != metadata.len() {
            anyhow::bail!("projected file changed while read: {}", path.display());
        }
        Ok(bytes)
    }

    /// Load a capsule into the Kernel from a directory containing a Capsule.toml
    ///
    /// # Errors
    ///
    /// Returns an error if the manifest cannot be loaded, the capsule cannot be created, or registration fails.
    #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
    async fn load_capsule(
        &self,
        dir: PathBuf,
        principal: &PrincipalId,
    ) -> Result<(), anyhow::Error> {
        self.verify_workspace_capsule_tree(&dir)?;

View on GitHub (pinned to affd8760f4)

Solutions

1. Retry the read; transient IO failures usually clear on a fresh attempt.
2. Freeze mutations to the projection during reads (quiesce writers).
3. Check disk/filesystem health for the underlying error.
4. If on a network mount, verify the export/handle is still valid.

let bytes = loop {
    match read_projection_file_nofollow(path) {
        Ok(b) => break b,
        Err(e) if e.to_string().contains("read projected file") && attempts < 3 => { attempts += 1; continue; }
        Err(e) => return Err(e),
    }
};

When it happens

Trigger: Read error mid-stream: disk IO error, file truncated/removed after open, or descriptor issues on network filesystems.

Common situations: Projection mutated concurrently (file replaced between open and read — note a separate 'changed while read' error covers size mismatch, this one covers hard IO failures); failing disk; NFS stale file handle.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• read capsule projection {}: {error}
• read capsule projection entry: {error}
• inspect capsule projection {}: {error}
• inspect projected file {}: {error}
• legacy state source is redirected: {}

AI-assisted analysis of astrid-runtime/astrid@affd8760f4 (2026-09-09). Data as JSON: /api/errors/f086b2b81d0014c9. Report an issue: GitHub.