caddy: Caddy Crashing Due To Nil Pointer Dereference

On a production server, getting the following error:

an 31 00:24:41 Dw-Haproxy caddy[2568599]: panic: runtime error: invalid memory address or nil pointer dereference
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: [signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x5651f2]
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: goroutine 907455 [running]:
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: bufio.(*Writer).Available(...)
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]:         bufio/bufio.go:646
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: bufio.(*Writer).Write(0x0, {0x2a11ac0?, 0xc006e4b880?, 0xc00a8516ab?})
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]:         bufio/bufio.go:664 +0x52
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: net/http.(*response).WriteHeader(0xc00a8515e0, 0x64)
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]:         net/http/server.go:1165 +0x20e
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: github.com/caddyserver/caddy/v2/modules/caddyhttp/reverseproxy.(*Handler).reverseProxy.func1(0xc00490ee40?, 0xc008249b00?)
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]:         github.com/caddyserver/caddy/v2@v2.6.2/modules/caddyhttp/reverseproxy/reverseproxy.go:783 +0x6f
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: net/http.(*persistConn).readResponse(0xc00a0a6120, {{}, 0xc008249b00, {0xc008249a00}, 0xc0096cd020, 0x0, 0xc0096ccf60, 0xc0096ccfc0}, 0xc008155880)
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]:         net/http/transport.go:2313 +0x20c
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: net/http.(*persistConn).readLoop(0xc00a0a6120)
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]:         net/http/transport.go:2108 +0x3aa
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]: created by net/http.(*Transport).dialConn
Jan 31 00:24:41 Dw-Haproxy caddy[2568599]:         net/http/transport.go:1751 +0x173e
Jan 31 00:24:41 Dw-Haproxy systemd[1]: caddy.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Jan 31 00:24:41 Dw-Haproxy systemd[1]: caddy.service: Failed with result 'exit-code'.

The config being used is:

sub.domain.tld {
        reverse_proxy localhost:8080 {
                #header_up X-Forwarded-For {header.Cf-Connecting-Ip} 
       }

        route /stats {
                reverse_proxy localhost:2087
        }

        handle_path /hidden/* {
                reverse_proxy 0.0.0.0:3000
        }
}

sub2.domain.tld {
        reverse_proxy localhost:8080
        route /stats {
                reverse_proxy localhost:2087
        }
}

The reverse_proxy 0.0.0.0:3000 part uses a different ip, and was replaced for 0.0.0.0 while sharing to hide sensitive info.

This has worked without issues for multiple months until today when crashes started. A simple restart fixes the issue and gets the application working.

➜  ~ caddy version
v2.6.2 h1:wKoFIxpmOJLGl3QXoo6PNbYvGW4xLEgo32GPBEjWL8o=