Stratum error, thread 'stratum_server' panicked at 'called Option::unwrap() on a None value':

[rlinxy]

Was running stratum for mining for 2 days without problem. But around 12 hours ago, got error as below, then all miners can not connect to the stratum.

20190118 14:45:37.270 ERROR grin_util::logger -
thread 'stratum_server' panicked at 'called Option::unwrap() on a None value': libcore/option.rs:355stack backtrace:
0: 0x55f48b7e79ed - backtrace::backtrace::trace::hd74837959dc31a2c
1: 0x55f48b7e6c02 - <backtrace::capture::Backtrace as core::default::Default>::default::hfbe03539066da14f
2: 0x55f48b7e6c79 - backtrace::capture::Backtrace::new::hd9d47426559d8b68
3: 0x55f48b770960 - grin_util::logger::send_panic_to_log::{{closure}}::h6b81febaf2dee014
4: 0x55f48b8b87b6 - std::panicking::rust_panic_with_hook::hde420d6fd4455550
at libstd/panicking.rs:480
5: 0x55f48b8b8301 - std::panicking::continue_panic_fmt::h8f394f3c578bcc76
at libstd/panicking.rs:390
6: 0x55f48b8b81e5 - rust_begin_unwind
at libstd/panicking.rs:325
7: 0x55f48b90225c - core::panicking::panic_fmt::hca5dc4e8b320bc56
at libcore/panicking.rs:77
8: 0x55f48b90218b - core::panicking::panic::hca17aeb7dac42859
at libcore/panicking.rs:52
9: 0x55f48b242bd9 - grin_servers::mining::stratumserver::StratumServer::handle_rpc_requests::h37641ad4ed0ad706
10: 0x55f48b2458ea - grin_servers::mining::stratumserver::StratumServer::run_loop::ha8ac7fd410c1993f
11: 0x55f48b2358d8 - std::sys_common::backtrace::__rust_begin_short_backtrace::h094e9a7f299b0a6b
12: 0x55f48b20e418 - std::panicking::try::do_call::h661125717ff9fb5c
13: 0x55f48b8ca859 - __rust_maybe_catch_panic
at libpanic_unwind/lib.rs:102
14: 0x55f48b2181d7 - <F as alloc::boxed::FnBox>::call_box::hdc56abe3a22a6fdf
15: 0x55f48b8b4d3d - <alloc::boxed::Box<(dyn alloc::boxed::FnBox<A, Output=R> + 'a)> as core::ops::function::FnOnce>::call_once::h9d902c911a417e39
at liballoc/boxed.rs:682
- std::sys_common::thread::start_thread::h44127e03e78ca137
at libstd/sys_common/thread.rs:24
16: 0x55f48b8a00b5 - std::sys::unix::thread::Thread::new::thread_start::h8f17b97f2223146c
at libstd/sys/unix/thread.rs:90
17: 0x7fa72c73b6b9 - start_thread
18: 0x7fa72c25b41c - clone
19: 0x0 -

[rlinxy]

The system is Ubuntu 16.04
Have tried both the 'grin' executable download from 'release' here and the one complied by myself, version 1.0.0
Thanks.

[rlinxy]

Seems it happens when some 'specific' miners trying to connect to the stratum server. I guess the code is here from line 306 to 310, /grin/servers/src/mining/stratumserver.rs
Still trying to figure it out. We may have to block a worker if it sent wrong data.

[rlinxy]

By reading the code hours, I am thinking if this happens due to some rig sent wrong data, why not just block it. Is it really neccessary to use 'unwrap' other than 'unwrap_or()'?

[ignopeverell]

Duplicate of #2421