Rare region loading test failure

[DomWilliams0]

Randomly happened once, haven't been able to trigger it again.. Unfortunately I didn't get the log output

---- region::regions::tests::region_requesting_separate_directions stdout ----
thread 'tokio-runtime-worker' panicked at 'internal error: entered unreachable code: region RegionLocation(6, 5) should be already requested', game/procgen/src/region/regions.rs:372:17
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'tokio-runtime-worker' panicked at 'Box<dyn Any>', game/procgen/src/region/regions.rs:896:9
thread 'region::regions::tests::region_requesting_separate_directions' panicked at 'Box<dyn Any>', game/procgen/src/region/regions.rs:896:9