kovidgoyal/kitty · error

Failed to download %s with error: %w

Error message

Failed to download %s with error: %w

What it means

fetch_cached performs an HTTP GET for a theme collection JSON; any transport-level failure from http.DefaultClient.Do (DNS, timeout, refused connection, TLS) is wrapped with the failing URL.

Source

Thrown at tools/themes/collection.go:390

				if time.Now().Before(cache_age.Add(max_cache_age)) {
					return cache_path, nil
				}
			}
		}
	}
	if max_cache_age < 0 {
		return "", ErrNoCacheFound
	}
	req, err := http.NewRequest(http.MethodGet, url, nil)
	if err != nil {
		return "", err
	}
	if jm.Etag != "" {
		req.Header.Add("If-None-Match", jm.Etag)
	}
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return "", fmt.Errorf("Failed to download %s with error: %w", url, err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		if resp.StatusCode == http.StatusNotModified {
			jm.Timestamp = utils.ISO8601Format(time.Now())
			comment, _ := json.Marshal(jm)
			err = set_comment_in_zip_file(cache_path, utils.UnsafeBytesToString(comment))
			if err != nil {
				return "", err
			}
			return cache_path, nil
		}
		return "", fmt.Errorf("Failed to download %s with HTTP error: %s", url, resp.Status)
	}
	var tf, tf2 *os.File
	tf, err = os.CreateTemp(filepath.Dir(cache_path), name+".temp-*")
	if err == nil {
		tf2, err = os.CreateTemp(filepath.Dir(cache_path), name+".temp-*")

View on GitHub (pinned to 6d5d0c4406)

Solutions

1. Check network connectivity and DNS resolution for the URL in the message
2. Set HTTPS_PROXY/HTTP_PROXY if behind a corporate proxy, or fix firewall rules
3. Retry after the transient outage; the cached copy (if any) remains usable
4. If using a custom URL, verify it is reachable with curl

resp, err := http.Head(url)
if err != nil || resp.StatusCode >= 400 { use local cache; skip refresh }

if _, err := collection.FetchCached(); err != nil { log.Printf("theme fetch failed (offline?): %v", err); fall back to bundled themes }

When it happens

Trigger: Fetching a theme collection when the machine is offline, DNS for the kitty themes host fails, a proxy blocks the request, or the request times out.

Common situations: Running kitten themes fetch behind restrictive networks/corporate proxies, transient internet outages, or a mistyped/customized collection URL.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

• Could not get
• This must be run as kitten themes
• No cache found and max cache age is negative
• Failed to read data from update check process, with error: {
• Failed to process update check data {raw!r}, with error: {e}

AI-assisted analysis of kovidgoyal/kitty@6d5d0c4406 (2026-08-27). Data as JSON: /api/errors/52174e81929adbd3. Report an issue: GitHub.