Seeing an panic in query.log while testing transactions

Here is the panic I got, not able to reproduce

repro:
In cbq shell
begin work;
note a transaction id.
Open new new cqb shell \set -txid noted value
run long running query in new shell
Run the same query original shell before finishing other one.

As both going to same transaction it must serialize execution one after other.

2020/09/24 16:10:59 http: panic serving 127.0.0.1:50492: runtime error: invalid memory address or nil pointer dereference
goroutine 115033 [running]:
net/http.(*conn).serve.func1(0xc000477220)
/Users/couchbase/.cbdepscache/exploded/x86_64/go-1.13.7/go/src/net/http/server.go:1767 +0x139
panic(0x531f4a0, 0x68f5d10)
/Users/couchbase/.cbdepscache/exploded/x86_64/go-1.13.7/go/src/runtime/panic.go:679 +0x1b2
github.com/couchbase/query/server.(*Server).handlePreTxRequest(0xc00051c540, 0x58fbb40, 0xc001e8f000, 0xc00051c5c0, 0xc00051c610, 0x0, 0x0)
/Users/couchbase/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/server/server.go:628 +0x16e
github.com/couchbase/query/server.(*Server).handlePlusRequest(0xc00051c540, 0x58fbb40, 0xc001e8f000, 0xc00051c5c0, 0xc00051c610, 0x9)
/Users/couchbase/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/server/server.go:592 +0xa7
github.com/couchbase/query/server.(*Server).PlusServiceRequest(0xc00051c540, 0x58fbb40, 0xc001e8f000, 0x0)
/Users/couchbase/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/server/server.go:528 +0x85
github.com/couchbase/query/server/http.(*HttpEndpoint).ServeHTTP(0xc0008654a0, 0x58819e0, 0xc000ab9420, 0xc001c10200)
/Users/couchbase/workspace/couchbase-server-unix/goproj/src/github.com/couchbase/query/server/http/service_endpoint.go:252 +0x2f4
github.com/gorilla/mux.(*Router).ServeHTTP(0xc0004621e0, 0x58819e0, 0xc000ab9420, 0xc001c10200)
/Users/couchbase/workspace/couchbase-server-unix/godeps/src/github.com/gorilla/mux/mux.go:114 +0xdb
net/http.serverHandler.ServeHTTP(0xc000a32000, 0x58819e0, 0xc000ab9420, 0xc001c10000)
/Users/couchbase/.cbdepscache/exploded/x86_64/go-1.13.7/go/src/net/http/server.go:2802 +0xa4
net/http.(*conn).serve(0xc000477220, 0x588cf20, 0xc00187c500)
/Users/couchbase/.cbdepscache/exploded/x86_64/go-1.13.7/go/src/net/http/server.go:1890 +0x875
created by net/http.(*Server).Serve
/Users/couchbase/.cbdepscache/exploded/x86_64/go-1.13.7/go/src/net/http/server.go:2928 +0x384