Testnet stability (#451)

* Change reduced tree for adding weightless node

* Add more comments for reduced tree fork choice

* Small refactor on reduced tree for readability

* Move test_harness forking logic into itself

* Add new `AncestorIter` trait to store

* Add unfinished tests to fork choice

* Make `beacon_state.genesis_block_root` public

* Add failing lmd_ghost fork choice tests

* Extend fork_choice tests, create failing test

* Implement Debug for generic ReducedTree

* Add lazy_static to fork choice tests

* Add verify_integrity fn to reduced tree

* Fix bugs in reduced tree

* Ensure all reduced tree tests verify integrity

* Slightly alter reduce tree test params

* Add (failing) reduced tree test

* Fix bug in fork choice

Iter ancestors was not working well with skip slots

* Put maximum depth for common ancestor search

Ensures that we don't search back past the finalized root.

* Add basic finalization tests for reduced tree

* Change fork choice to use beacon_block_root

Previously it was using target_root, which was wrong

* Change reduced tree for adding weightless node

* Add more comments for reduced tree fork choice

* Small refactor on reduced tree for readability

* Move test_harness forking logic into itself

* Add new `AncestorIter` trait to store

* Add unfinished tests to fork choice

* Make `beacon_state.genesis_block_root` public

* Add failing lmd_ghost fork choice tests

* Extend fork_choice tests, create failing test

* Implement Debug for generic ReducedTree

* Add lazy_static to fork choice tests

* Add verify_integrity fn to reduced tree

* Fix bugs in reduced tree

* Ensure all reduced tree tests verify integrity

* Slightly alter reduce tree test params

* Add (failing) reduced tree test

* Fix bug in fork choice

Iter ancestors was not working well with skip slots

* Put maximum depth for common ancestor search

Ensures that we don't search back past the finalized root.

* Add basic finalization tests for reduced tree

* Add network dir CLI flag

* Simplify "NewSlot" log message

* Rename network-dir CLI flag

* Change fork choice to use beacon_block_root

Previously it was using target_root, which was wrong

* Update db dir size for metrics

* Change slog to use `FullFormat` logging

* Update some comments and log formatting

* Add prom gauge for best block root

* Only add known target blocks to fork choice

* Add finalized and justified root prom metrics

* Add CLI flag for setting log level

* Add logger to beacon chain

* Add debug-level CLI flag to validator

* Allow block processing if fork choice fails

* Create warn log when there's low libp2p peer count

* Minor change to logging

* Make ancestor iter return option

* Disable fork choice test when !debug_assertions

* Fix type, removed code fragment

* Tidy some borrow-checker evading

* Lower reduced tree random test iterations

beacon_node/beacon_chain/src/test_utils.rs

@@ -1,5 +1,6 @@
 use crate::{BeaconChain, BeaconChainTypes, BlockProcessingOutcome};
 use lmd_ghost::LmdGhost;
+use sloggers::{null::NullLoggerBuilder, Build};
 use slot_clock::SlotClock;
 use slot_clock::TestingSlotClock;
 use state_processing::per_slot_processing;
@@ -94,6 +95,9 @@ where
         let mut genesis_block = BeaconBlock::empty(&spec);
         genesis_block.state_root = Hash256::from_slice(&genesis_state.tree_hash_root());
 
+        let builder = NullLoggerBuilder;
+        let log = builder.build().expect("logger should build");
+
         // Slot clock
         let slot_clock = TestingSlotClock::new(
             spec.genesis_slot,
@@ -107,6 +111,7 @@ where
             genesis_state,
             genesis_block,
             spec.clone(),
+            log,
         )
         .expect("Terminate if beacon chain generation fails");