What causes "download %s fail" in XX-net/XX-Net?

Check network/proxy connectivity: can you curl the logged URL?

download %s fail

Error message

download %s fail

What it means

While iterating module download URLs, download_file(url, file_path) returned False and the launcher logs 'download %s fail' and continues to the next candidate URL. This is a per-URL network failure, not fatal; other mirrors may still succeed.

Source

Thrown at code/default/launcher/update.py:186

    import os
    global update_content, update_dict

    current_path = os.path.dirname(os.path.abspath(__file__))
    download_path = os.path.abspath(os.path.join(current_path, os.pardir, os.pardir, 'data', 'downloads'))
    if not os.path.isdir(download_path):
        os.mkdir(download_path)

    try:
        for source in update_dict["modules"][module]["versions"][new_version]["sources"]:
            url = source["url"]
            filename = module + "-" + new_version + ".zip"

            file_path = os.path.join(download_path, filename)

            if os.path.isfile(file_path) and sha1_file(file_path) == update_dict["modules"][module]["versions"][new_version]["sha1"]:
                pass
            elif not download_file(url, file_path):
                xlog.warn("download %s fail", url)
                continue

            sha1 = sha1_file(file_path)
            if update_dict["modules"][module]["versions"][new_version]["sha1"] != sha1:
                xlog.warn("download %s sha1 wrong", url)
                continue

            module_path = os.path.abspath(os.path.join(current_path, os.pardir, os.pardir, module))
            if not os.path.isdir(module_path):
                os.mkdir(module_path)

            version_path = os.path.join(module_path, new_version)
            if os.path.isdir(version_path):
                xlog.error("module dir exist:%s, download exist.", version_path)
                return

            with zipfile.ZipFile(file_path, "r") as dz:
                dz.extractall(module_path)

View on GitHub (pinned to cfa5bc17b6)

Solutions

Check network/proxy connectivity: can you curl the logged URL?
Retry the update later — the downloader tries multiple mirrors and transient failures are common
Verify the launcher's own proxy settings are correct (a broken local proxy breaks update downloads)
If all URLs fail, inspect update_from_github.download_file logs for the underlying exception

Defensive patterns

Strategy: retry

Validate before calling

def url_reachable(url, timeout=10):
    import urllib.request
    try:
        urllib.request.urlopen(urllib.request.Request(url, method='HEAD'), timeout=timeout)
        return True
    except Exception:
        return False

Try / catch

for url in urls:
    try:
        download_file(url, path)
        break
    except Exception as e:
        log.warning('download failed %s: %r', url, e)
        continue

Prevention

Provide multiple mirror URLs (the downloader already continues to the next)
Check the local proxy before triggering updates
Retry updates on flaky networks instead of investigating immediately

When it happens

Trigger: download_module calling download_file for a module URL when the request raises/times out or returns a non-200 status inside update_from_github.download_file, causing it to return False.

Common situations: One mirror unreachable (GFW blocking, server down, DNS failure, proxy misconfigured); the loop usually recovers via the next URL in the list.

Related errors

AI-assisted analysis of XX-net/XX-Net@cfa5bc17b6 (2026-08-27). Data as JSON: /api/errors/ba46d1f95cf89f6e. Report an issue: GitHub.