thread 'RenderBackend' panicked at 'called `Option::unwrap()` on a `None` value', /checkout/src/libcore/option.rs:335:20
stack backtrace:
   0:     0x7f89cd640233 - std::sys::imp::backtrace::tracing::imp::unwind_backtrace::hcdf51e4c9dc54357
                               at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1:     0x7f89cd63d13f - std::panicking::default_hook::{{closure}}::h46820a72bf0cb624
                               at /checkout/src/libstd/sys_common/backtrace.rs:71
                               at /checkout/src/libstd/sys_common/backtrace.rs:60
                               at /checkout/src/libstd/panicking.rs:380
   2:     0x7f89cd63c58d - std::panicking::default_hook::h4c1ef1cc83189c8e
