dotnet/runtime · error · Exception

Failed to download {url}, Status Code: {response.status}

Error message

Failed to download {url}, Status Code: {response.status}

What it means

download_file received an HTTP response with a status code other than 200 (e.g. 404 Not Found, 403 Forbidden, 500/502/503 server error). The exception captures the status so the caller can see why the .deb or Release file could not be fetched. The function then retries up to max_retries before giving up.

Source

Thrown at eng/common/cross/install-debs.py:40

    attempt = 0
    while attempt < max_retries:
        try:
            async with session.get(url, timeout=aiohttp.ClientTimeout(total=timeout)) as response:
                if response.status == 200:
                    with open(dest_path, "wb") as f:
                        content = await response.read()

                        # verify checksum if provided
                        if checksum:
                            sha256 = hashlib.sha256(content).hexdigest()
                            if sha256 != checksum:
                                raise Exception(f"SHA256 mismatch for {url}: expected {checksum}, got {sha256}")

                        f.write(content)
                    print(f"Downloaded {url} at {dest_path}")
                    return
                else:
                    raise Exception(f"Failed to download {url}, Status Code: {response.status}")
        except (asyncio.CancelledError, asyncio.TimeoutError, aiohttp.ClientError) as e:
            print(f"Error downloading {url}: {type(e).__name__} - {e}. Retrying...")

        attempt += 1
        await asyncio.sleep(retry_delay)

    raise Exception(f"Failed to download {url} after {max_retries} attempts.")

async def download_deb_files_parallel(mirror, packages, tmp_dir):
    """Download .deb files in parallel."""
    os.makedirs(tmp_dir, exist_ok=True)

    tasks = []
    timeout = aiohttp.ClientTimeout(total=60)
    async with aiohttp.ClientSession(timeout=timeout) as session:
        for pkg, info in packages.items():
            filename = info.get("Filename")
            if filename:

View on GitHub (pinned to 60108ba66e)

Solutions

1. Verify --arch and --suite match a mirror layout that actually contains the package (browse the mirror's dists/<suite>/ directory).
2. Switch to a mirror that still hosts the package, or pick a newer --suite.
3. If 4xx is intermittent (rate limit/CDN), wait and retry; for 5xx pick a different mirror.
4. Make sure the base-packages list (dpkg, busybox, libc6, etc.) is available on the chosen mirror.

Example fix

# before
python3 install-debs.py --arch loong64 --suite sid --mirror http://deb.debian.org/debian libc6
# 404: sid does not carry loong64 at deb.debian.org

# after
python3 install-debs.py --arch loong64 --suite sid --mirror http://ftp.ports.debian.org/debian-ports libc6

# Pre-flight: probe a HEAD request for each .deb URL before the build.
import aiohttp, asyncio
async def probe(url: str) -> int:
    async with aiohttp.ClientSession() as s:
        async with s.head(url) as r:
            return r.status

# If status != 200, fix --arch/--suite/--mirror before running install-debs.py.

# download_file already retries 3x. For 4xx, fix the mirror/suite/arch instead of retrying:
try:
    main()
except Exception as e:
    if 'Status Code: 40' in str(e):
        print('Package path not found; check --arch/--suite/--mirror.')
        sys.exit(2)
    raise

When it happens

Trigger: Fetching a .deb by the path stored in the Packages index, but the mirror returns 404 (package retired, suite changed, arch mismatch). Or a 403/5xx due to mirror problems. Raised at install-debs.py:40 inside the retry loop.

Common situations: Pointing --suite at a released Debian/Ubuntu version where a package was removed. Wrong --arch (e.g. arm64 against an amd64-only mirror). Mirror rate-limiting returning 403. Mirror maintenance returning 5xx.

Related errors

• Failed to download {url} after {max_retries} attempts.
• SHA256 mismatch for {url}: expected {checksum}, got {sha256}
• SHA256 mismatch for {path}: expected {packages_sha}, got {sh
• Signature verification failed: {result.stderr.decode('utf-8'
• Could not find checksum for {path} in Release file.

AI-assisted analysis of dotnet/runtime@60108ba66e (2026-08-10). Data as JSON: /api/errors/8c3c59b871ce1355. Report an issue: GitHub.