Check Windows curl for SSPI Before Using Native Proxy Credentials

Ask the job's actual executable for its feature report:

curl.exe --version

NTLM identifies an authentication method. SSPI integrates with Windows security facilities. For a Windows SSPI-enabled build and an NTLM proxy, the documented current-context form is:

curl.exe --proxy http://proxy.example.net:8080 --proxy-ntlm --proxy-user : https://service.example.net/

The single colon selects credentials from the current environment; it is not an empty explicit password recipe for every build. The proxy must offer the selected method and accept that identity. When the exchange still fails, trace the NTLM challenge flow on that route.

Keep the process account in the comparison. A scheduled task or service has a different security context from the browser's desktop user.

Use reported capabilities rather than an old fixed-version recommendation. The TLS backend and HTTPS-proxy support remain separate features when those connections are required.