HTTP/3 getsockname Bad file descriptor

[Ryan Gould]

hello all you amazing developers,

i found some old 2013 references to this error relating to SPDY, but 
have not seen anything recently.  i am building on a debian 9 box using 
the latest code from here: https://hg.nginx.org/nginx-quic using build 
instructions from https://quic.nginx.org/readme.html

i get the following errors when i use firefox nightly (82.0b8), 
Chrome/85, or when i use command-line curl (built using quiche):

2020/10/07 04:35:04 [alert] 14263#0: *78 getsockname() failed (9: Bad 
file descriptor), client: X.X.X.X, server: example.com, request: "HEAD / 
HTTP/3"
2020/10/07 04:35:04 [alert] 14263#0: *78 getsockname() failed (9: Bad 
file descriptor) while sending response to client, client: X.X.X.X, 
server: example.com, request: "HEAD / HTTP/3"

i dont know if it is related, but i am also not having any success 
getting 0-RTT or passing the QUIC test (but HTTP/3 passes) on 
https://www.http3check.net/

otherwise, firefox and chrome think they are using HTTP/3 successfully.

if i can help with logs, please let me know.