What causes "download size:%d, need size:%d, download fail." in XX-net/XX-Net?

Check network/proxy stability and retry the update (the loop already tries the next URL).

download size:%d, need size:%d, download fail.

Error message

download size:%d, need size:%d, download fail.

What it means

Logged when a chunked HTTP download finishes but the total bytes written do not equal the Content-Length recorded for that URL. The downloader loops URLs and continues to the next candidate, so this is a size-mismatch failure of one mirror, not necessarily a total failure.

Source

Thrown at code/default/launcher/update_from_github.py:146

                left = file_size
                downloaded = 0
                with open(filename, 'wb') as fp:
                    while global_var.running:
                        chunk_len = min(65536, left)
                        if not chunk_len:
                            break

                        chunk = req.read(chunk_len)
                        if not chunk:
                            break
                        fp.write(chunk)
                        downloaded += len(chunk)
                        progress[url]["downloaded"] = downloaded
                        left -= len(chunk)

            if downloaded != progress[url]["size"]:
                xlog.warn("download size:%d, need size:%d, download fail.", downloaded, progress[url]["size"])
                continue
            else:
                progress[url]["status"] = "finished"
                return True
        except Exception as e:
            xlog.exception("download %s to %s fail:%r", url, filename, e)
            continue

    progress[url]["status"] = "failed"
    return False


def parse_update_versions(readme_file):
    versions = []
    try:
        fd = open(readme_file, "rb")
        lines = fd.readlines()
        p = re.compile(br'https://codeload.github.com/XX-net/XX-Net/zip/([0-9]+)\.([0-9]+)\.([0-9]+) ([0-9a-fA-F]*)')

View on GitHub (pinned to cfa5bc17b6)

Solutions

Check network/proxy stability and retry the update (the loop already tries the next URL).
Verify the URL list in get_github_versions() is reachable with curl -I and compare Content-Length.
If a specific mirror is persistently bad, remove/replace that URL in the version metadata.
Ensure disk space on the download path.

Defensive patterns

Strategy: retry

Try / catch

// treat download_file as fallible; it already rotates URLs
if not download_file(url_list, filename):
    raise UpdateDownloadError('all mirrors failed for %s' % filename)

Prevention

Monitor progress[url]['status'] instead of assuming success.
Run updates on a stable network path.
Pre-check disk space before update.

When it happens

Trigger: download_file() completes its read loop (or breaks early on a short stream) and downloaded != progress[url]['size']; typical with truncated responses from GitHub/raw.githubusercontent mirrors, proxies closing early, or a redirect page returned instead of the binary.

Common situations: Updating XX-Net behind an unstable proxy or firewall where GitHub responses are cut off; a mirror returning an HTML error page with a different Content-Length; disk full mid-write.

Related errors

AI-assisted analysis of XX-net/XX-Net@cfa5bc17b6 (2026-08-27). Data as JSON: /api/errors/42a761ab3f6ef2ff. Report an issue: GitHub.