Network errors during wheel cache lookup are silently swallowed in _download_wheel_from_cache()

[LalatenduMohanty]

Summary

In bootstrapper.py:1054-1058, a bare except Exception catches all errors during wheel cache lookup — including network timeouts, DNS failures, and auth errors — and treats them identically to "wheel not found", silently falling through to an expensive source build.

Problem

# bootstrapper.py lines 1054-1058
except Exception:
    logger.info(
        f"did not find wheel for {resolved_version} in {self.cache_wheel_server_url}"
    )
    return None, None

The entire _download_wheel_from_cache() method (lines 1008-1058) is wrapped in a single try/except. This catches:

• requests.ConnectionError (DNS failure, refused connection)
• requests.Timeout (server not responding)
• requests.HTTPError (401 Unauthorized, 403 Forbidden)
• Any other unexpected exception

All are logged at INFO level with a misleading "did not find wheel" message and return (None, None) — the same result as a genuinely missing wheel. The caller then proceeds to build from source.

Testing suggestions

• Verify that legitimate "not found" errors (e.g. ResolverException) are still handled gracefully and return (None, None).