wasmerio/wasmer · error · anyhow::Error

Could not find package with hash '{h}'

Error message

Could not find package with hash '{h}'

What it means

fetch_webc_package resolves a PackageIdent to a downloadable webc URL. When the ident is a content hash (PackageIdent::Hash), it looks up the package release via get_package_release; if the backend returns None, it bails with 'Could not find package with hash {h}'. Name/version idents use a different URL construction and don't hit this path.

Source

Thrown at lib/backend-api/src/query.rs:777

/// Load a webc package from the registry.
///
/// NOTE: this uses the public URL instead of the download URL available through
/// the API, and should not be used where possible.
pub async fn fetch_webc_package(
    client: &WasmerClient,
    ident: &PackageIdent,
    default_registry: &Url,
) -> Result<Container, anyhow::Error> {
    let url = match ident {
        PackageIdent::Named(n) => Url::parse(&format!(
            "{default_registry}/{}:{}",
            n.full_name(),
            n.version_or_default()
        ))?,
        PackageIdent::Hash(h) => match get_package_release(client, &h.to_string()).await? {
            Some(webc) => Url::parse(&webc.webc_url)?,
            None => anyhow::bail!("Could not find package with hash '{h}'"),
        },
    };

    let data = client
        .client
        .get(url)
        .header(reqwest::header::USER_AGENT, &client.user_agent)
        .header(reqwest::header::ACCEPT, "application/webc")
        .send()
        .await?
        .error_for_status()?
        .bytes()
        .await?;

    from_bytes(data).context("failed to parse webc package")
}

/// Fetch app templates.

View on GitHub (pinned to 8c4b9ee9d3)

Solutions

1. Verify the hash against `wasmer package publish` output or the registry web UI and re-copy it.
2. Resolve the package by name+version instead of hash (PackageIdent::Named) to fetch the latest release.
3. Re-publish the artifact if it was never pushed or was deleted, then use the new hash.
4. Confirm the client points at the registry that actually hosts this hash.

Example fix

// before
let url = fetch_webc_package(&client, &PackageIdent::Hash(h)).await?;
// after
let url = match fetch_webc_package(&client, &PackageIdent::Hash(h.clone())).await {
    Ok(u) => u,
    Err(_) => fetch_webc_package(&client, &PackageIdent::Named(PackageId::new("ns/pkg", Some(version)))).await?,
};

match fetch_webc_package(&client, &PackageIdent::Hash(h)).await {
    Ok(url) => url,
    Err(e) if e.to_string().contains("Could not find package with hash") => {
        // fall back to name+version resolution or surface a clear 'unknown hash' error
        fetch_webc_package(&client, &named_ident).await
    }
    Err(e) => return Err(e),
};

When it happens

Trigger: Calling fetch_webc_package with PackageIdent::Hash where the hash does not correspond to any published package release on the registry (unknown, unpublished, or malformed-but-parseable hash).

Common situations: Hash copied from another registry/environment; package deleted or re-published so the old hash is gone; hash referencing a locally built artifact never pushed; typos when pinning by hash.

Related errors

• cron job '{cron_job}' not found
• user agent must not be empty
• invalid value for {} - expected 0/false|1/true: '{other}'
• invocation start must not be after end
• invalid node type returned

AI-assisted analysis of wasmerio/wasmer@8c4b9ee9d3 (2026-09-01). Data as JSON: /api/errors/df38f9ad132cbd07. Report an issue: GitHub.