What causes "failed to fetch release: {:?}" in zed-industries/zed?

Retry after a few minutes - most release-fetch failures are transient.

failed to fetch release: {:?}

Error message

failed to fetch release: {:?}

What it means

Zed's auto-updater fetched release metadata over HTTP and the response status was not 2xx; the message embeds the raw response body, which usually names the real cause (404 for a missing channel build, 403 from a proxy, 5xx during an outage).

Source

Thrown at crates/auto_update/src/auto_update.rs:691

        let url = http_client.build_zed_cloud_url_with_query(
            &path,
            AssetQuery {
                os,
                arch,
                asset,
                metrics_id: metrics_id.as_deref(),
                system_id: system_id.as_deref(),
                is_staff,
            },
        )?;

        let mut response = http_client
            .get(url.as_str(), Default::default(), true)
            .await?;
        let mut body = Vec::new();
        response.body_mut().read_to_end(&mut body).await?;

        anyhow::ensure!(
            response.status().is_success(),
            "failed to fetch release: {:?}",
            String::from_utf8_lossy(&body),
        );

        serde_json::from_slice(body.as_slice()).with_context(|| {
            format!(
                "error deserializing release {:?}",
                String::from_utf8_lossy(&body),
            )
        })
    }

    async fn update(this: Entity<Self>, cx: &mut AsyncApp) -> Result<()> {
        let (client, installed_version, previous_status, release_channel) =
            this.read_with(cx, |this, cx| {
                (
                    this.client.http_client(),

View on GitHub (pinned to bc538def45)

Solutions

Retry after a few minutes - most release-fetch failures are transient.
curl -i the release URL (e.g. https://zed.dev/api/releases/stable/latest) to see the exact status and body.
Verify the release channel (stable/preview/nightly) exists for your platform and commit.
Remove or fix custom update-URL environment overrides.

Defensive patterns

Strategy: retry

Validate before calling

// pre-flight before the update check
let probe = http_client.head("https://zed.dev/api/releases/stable/latest").await;
if probe.is_err() {
    // defer the update check until the network is reachable
}

Try / catch

wrap the update check in retry-with-backoff; match errors containing "failed to fetch release" and retry up to N times before reporting; treat 5xx as transient and 4xx as terminal.

Prevention

Pin a valid release channel in settings
Do not override update URLs unless you control the endpoint
Retry update checks after network transitions instead of failing once

When it happens

Trigger: http_client.get(url) for the release endpoint completes with a non-success status while checking for updates on any channel, so the ensure! on response.status().is_success() fails before the JSON is parsed.

Common situations: Corporate proxies or captive portals injecting error pages; nightly/preview channel assets yanked or not yet published; zed.dev incidents; a custom ZED_UPDATE_URL / UPDATE_URL override pointing at a wrong endpoint.

Related errors

AI-assisted analysis of zed-industries/zed@bc538def45 (2026-08-16). Data as JSON: /api/errors/f1079ccdc132444f. Report an issue: GitHub.