goproxy actually discard all upstream errors, you can find its error
handling here [1], the upstream error from proxy.connectDial() is always
hidden in the two if branches, and never got logged. we need to log
hysteria layer errors by ourselves.
[1] 8ea89ba920/https.go (L321-L328)
according to some bug reports (such like #404 and the resolve_preference
one report via telegram private message), some users use http proxy, got a
http 502 error without any useful logs.
- UDP support has been temporarily removed, pending upstream QUIC library support for unreliable messages
- SOCKS5 server needs some rework
- Authentication
