sock:receive() timeout on unix socket results in SIGSEGV

I noticed that such code in my content_by_lua block

local sock = ngx.socket.udp()
sock:setpeername('unix:/run/validator')

sock:send({ some, data, here })

sock:settimeout(2000) -- milis
local okay  = sock:receive()

if socket not listening, produces this in error.log

2022/11/19 12:11:18 [crit] 79811#79811: *1 connect() failed (111: Connection refused), client: ::1, server: ...
2022/11/19 12:11:18 [error] 79811#79811: *1 send() failed (107: Transport endpoint is not connected), client: ::1, server: ...
2022/11/19 12:11:20 [alert] 79809#79809: worker process 79811 exited on signal 11 (core dumped)

First two messages are expected. The last is not. Why timeout expiry crashes worker with SIGSEGV?? Do I miss anything?

Server: openresty/1.21.4.1

Reproduce the Lua code using sock:receive() after the Unix socket connection is refused, then inspect the resulting worker core dump and the socket receive path. Done means the timeout or failed socket is handled without a SIGSEGV while the expected connection errors remain visible.