legoktm@mwmaint2002:~$ https_proxy=localhost:6501 curl 'https://meta.wikimedia.org/w/api.php?action=query&meta=siteinfo&format=json'
curl: (56) Received HTTP code 404 from proxy after CONNECT
legoktm@mwmaint2002:~$ https_proxy=localhost:6501 curl 'https://meta.wikimedia.org/w/api.php?action=query&meta=siteinfo&format=json' -vvv
*   Trying ::1...
* TCP_NODELAY set
* connect to ::1 port 6501 failed: Connection refused
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to (nil) (127.0.0.1) port 6501 (#0)
* Establish HTTP proxy tunnel to meta.wikimedia.org:443
> CONNECT meta.wikimedia.org:443 HTTP/1.1
> Host: meta.wikimedia.org:443
> User-Agent: curl/7.52.1
> Proxy-Connection: Keep-Alive
> 
< HTTP/1.1 404 Not Found
< date: Wed, 25 Aug 2021 16:11:47 GMT
< server: envoy
< connection: close
< content-length: 0
< 
* Received HTTP code 404 from proxy after CONNECT
* Curl_http_done: called premature == 0
* Closing connection 0
curl: (56) Received HTTP code 404 from proxy after CONNECT