The loader has been tested with the presets published by Lighthouse.
You can try connecting to one of their testnets by running:
cd nim-beacon-chain
./connect-to-testnet lighthouse/testnet0
* rename compute_epoch_of_slot(...) to compute_epoch_at_slot(...)
* remove some unnecessary imports; remove some crosslink-related code and tests; complete renaming of compute_epoch_of_slot(...) to compute_epoch_at_slot(...)
* rm more transfer-related code and tests; rm more unnecessary strutils imports
* rm remaining unused imports
* remove useless get_empty_per_epoch_cache(...)/compute_start_slot_of_epoch(...) calls
* rename compute_start_slot_of_epoch(...) to compute_start_slot_at_epoch(...)
* rename ACTIVATION_EXIT_DELAY to MAX_SEED_LOOKAHEAD
* update domain types to 0.9.0
* mark AttesterSlashing, IndexedAttestation, AttestationDataAndCustodyBit, DepositData, BeaconBlockHeader, Fork, integer_squareroot(...), and process_voluntary_exit(...) as 0.9.0
* mark increase_balance(...), decrease_balance(...), get_block_root(...), CheckPoint, Deposit, PendingAttestation, HistoricalBatch, is_active_validator(...), and is_slashable_attestation_data(...) as 0.9.0
* mark compute_activation_exit_epoch(...), bls_verify(...), Validator, get_active_validator_indices(...), get_current_epoch(...), get_total_active_balance(...), and get_previous_epoch(...) as 0.9.0
* mark get_block_root_at_slot(...), ProposerSlashing, get_domain(...), VoluntaryExit, mainnet preset Gwei values, minimal preset max operations, process_block_header(...), and is_slashable_validator(...) as 0.9.0
* mark makeWithdrawalCredentials(...), get_validator_churn_limit(...), get_total_balance(...), is_valid_indexed_attestation(...), bls_aggregate_pubkeys(...), initial genesis value/constants, Attestation, get_randao_mix(...), mainnet preset max operations per block constants, minimal preset Gwei values and time parameters, process_eth1_data(...), get_shuffled_seq(...), compute_committee(...), and process_slots(...) as 0.9.0; partially update get_indexed_attestation(...) to 0.9.0 by removing crosslink refs and associated tests
* mark initiate_validator_exit(...), process_registry_updates(...), BeaconBlock, Eth1Data, compute_domain(...), process_randao(...), process_attester_slashing(...), get_base_reward(...), and process_slot(...) as 0.9.0
* fix network sim
* mark BeaconState, state list/vector lengths, misc values, get_base_reward(...), verifyStateRoot(...), and process_slot(...) as 0.8.3; update minimal/mainnet config initial values to 0.8.3 by removing GENESIS_FORK_VERSION
* remove some low-hanging perf silliness from get_winning_crosslink_and_attesting_indices(...) and switch inner/outer loop nesting order to get 10-15x function speedup for 128 and 512 validator cases by avoiding accidentally quadratic behavior, while keeping function signature unchanged and allowing easy ongoing verification of correctness of optimization
* avoid memory allocation with an openarray rather than seq
* update get_crosslink_deltas(...) to 0.8.0
* move non-spec ValidatorSetDeltaFlags from datatypes.nim to sync_protocol; fix mainnet MIN_ATTESTATION_INCLUSION_DELAY preset; update get_attestation_deltas(...) to 0.8.0; for 512 validators, get 90x speedup for get_attestation_deltas(...) from 179s to 2s
* explain purpose of when false portions, so they can be removed once accomplished
* replace BeaconState.finalized_{epoch,root} with BeaconState.finalized_checkpoint; rename get_delayed_activation_exit_epoch(...) to compute_activation_exit_epoch(...) and mark as 0.8.0; update get_churn_limit(...)/get_validator_churn_limit(...) to 0.8.0; update process_registry_updates(...) to 0.8.0
* update process_crosslinks(...) to 0.8.0; mark compute_start_slot_of_epoch(...) and get_committee_count(...) as 0.8.0
* mark Fork, is_slashable_validator(...), and get_beacon_proposer_index(...) as 0.8.0
* rename LATEST_SLASHED_EXIT_LENGTH to EPOCHS_PER_SLASHINGS_VECTOR; update process_slashings(...) to 0.8.0; remove pointless type conversion warning in get_previous_epoch(...)
* convert remaining references to finalized_epoch to finalized_checkpoint.epoch
* update slash_validator(...) to 0.8.0; mark inital value, Gwei, and time constants as 0.8.0; mark hash(...) and processBlockHeader(...) as 0.8.0
* rename WHISTLEBLOWING_REWARD_QUOTIENT to WHISTLEBLOWER_REWARD_QUOTIENT; rename LATEST_ACTIVE_INDEX_ROOTS_LENGTH to EPOCHS_PER_HISTORICAL_VECTOR (randao will also get merged into this); remove get_active_index_root(...); mark time parameter, signature domain types, and max operations per block constants as 0.8.0; update rewards and penalties constants to 0.8.0
* update is_valid_indexed_attestation(...) to 0.8.0; mark process_slot(...) as 0.8.0
* replace BeaconState.{current,previous}_justified_{epoch,root} with BeaconState.{current,previous}_justified_checkpoint
* rename slot_to_epoch(...) to compute_epoch_of_slot(...)
* rename aggregation_bitfield/custody_bitfield fields to aggregation_bits/custody_bits; rename convert_to_indexed(...) to get_indexed_attestation(...); mark BeaconBlockHeader as 0.8.0; update minimal preset MIN_ATTESTATION_INCLUSION_DELAY/time parameters in general to 0.8
* fix beacon node compilation; it used slightly different capitalizations of slot_to_epoch/slotToEpoch
* mark integer_squareroot(...), Deposit, VoluntaryExit, and Transfer as 0.8.0; rename get_epoch_start_slot(...) to compute_start_slot_of_epoch(...)
* add new Domain alias for uint64; rename bls_domain(...) to compute_domain(...), MAX_INDICES_PER_ATTESTATION to MAX_VALIDATORS_PER_COMMITTEE, and SignatureDomain to DomainType; update get_domain(...) to 0.8.0
* update/mark initiate_validator_exit(...) and Crosslink as 0.8.0; rename BeaconState.latest_block_roots -> BeaconState.block_roots; mark HistoricalBatch as 0.8.0
* update Deposit and BeaconBlockHeader to 0.7.0
* update get_total_balance(...) and get_base_reward(...) to 0.7.0
* rename initial value constant BLS_WITHDRAWAL_PREFIX_BYTE to BLS_WITHDRAWAL_PREFIX
* mark minimal presets as entirely migrated to 0.7.0; update process_rewards_and_penalties(...) to 0.7.0
* specify that targeting 0.7.0; adopt 0.7.0 refactoring of bls_domain/get_domain to update get_domain(...) to 0.7.0; mark that mainnet constant presets and block header processing are 0.7.0-consistent; update process_justification_and_finalization to 0.7.0 to fix potential underflow errors
* address mratsim's comment to copy whole spec comment
* 0.7.0 updates which don't change semantics; mostly comment changes
* mark get_attesting_indices, bls_verify, ProposerSlashing, BeaconBlockBody, deposit contract constants, state list length constants, compute_committee, get_crosslink_committee, is_slashable_attestation_data, processAttesterSlashings as 0.7.0; rename BASE_REWARD_QUOTIENT to BASE_REWARD_FACTOR
* complete marking unchanged-in-0.7.0 datatypes as such; a few more have trivial field renamings, etc
* update IndexedAttestation, verify_slashable_attestation/verify_indexed_attestation, and attester slashing processing to 0.6.3
* rm debug scaffolding
* rename Attestation.aggregate_signature -> Attestation.signature; convert various references to AttestationData.slot to get_attestation_slot; implement convert_to_indexed; update checkAttestation and processAttestations to 0.6.3; remove spurious assertion in beacon node related to invalid attestations
* replace 0.5 get_winning_root_and_participants with 0.6 get_winning_crosslink_and_attesting_indices; update process_crosslinks to 0.6.3
* mark both remaining 0.6.0 spec implementations as 0.6.3
* clear out all remaining spec version 0.6.1 refs
* GENESIS_SLOT and GENESIS_EPOCH are 0
* rm 0.5 get_attestation_participants in favor of 0.6 get_attesting_indices
* address mratsim's comment
* time can be equal to genesis
* fix invalid block assertions; those were essentially spurious
* allow toBeaconTime to handle time before genesis (in accordance with now(...) which states time can exist before GENESIS)
* update process_justification_and_finalization to 0.6.2; mark AttesterSlashing as 0.6.2
* replace get_effective_balance(...) with state.validator_registry[idx].effective_balance; rm get_effective_balance, process_ejections, should_update_validator_registry, update_validator_registry, and update_registry_and_shuffling_data; update get_total_balance to 0.6.2; implement process_registry_updates
* rm exit_validator; implement is_slashable_attestation_data; partly update processAttesterSlashings
* mark HistoricalBatch and Eth1Data as 0.6.2; implement get_shard_delta(...); replace 0.5 finish_epoch_update with 0.6 process_final_updates
* mark increase_balance, decrease_balance, get_delayed_activation_exit_epoch, bls_aggregate_pubkeys, bls_verify_multiple, Attestation, Transfer, slot_to_epoch, Crosslink, get_current_epoch, int_to_bytes*, various constants, processEth1Data, processTransfers, and verifyStateRoot as 0.6.2; rm is_double_vote and is_surround_vote
* mark get_bitfield_bit, verify_bitfield, ProposerSlashing, DepositData, VoluntaryExit, PendingAttestation, Fork, integer_squareroot, get_epoch_start_slot, is_active_validator, generate_seed, some constants to 0.6.2; rename MIN_PENALTY_QUOTIENT to MIN_SLASHING_PENALTY_QUOTIENT
* rm get_previous_total_balance, get_current_epoch_boundary_attestations, get_previous_epoch_boundary_attestations, and get_previous_epoch_matching_head_attestations
* update BeaconState to 0.6.2; simplify legacy get_crosslink_committees_at_slot infrastructure a bit by noting that registry_change is always false; reimplment 0.5 get_crosslink_committees_at_slot in terms of 0.6 get_crosslink_committee
* mark process_deposit(...), get_block_root_at_slot(...), get_block_root(...), Deposit, BeaconBlockHeader, BeaconBlockBody, hash(...), get_active_index_root(...), various constants, get_shard_delta(...), get_epoch_start_shard(...), get_crosslink_committee(...), processRandao(...), processVoluntaryExits(...), cacheState(...) as 0.6.2
* rm removed-since-0.5 split(...), is_power_of_2(...), get_shuffling(...); rm 0.5 versions of get_active_validator_indices and get_epoch_committee_count; add a few tests for integer_squareroot
* mark bytes_to_int(...) and advanceState(...) as 0.6.2
* rm 0.5 get_attesting_indices; update get_attesting_balance to 0.6.2
* another tiny commit to poke AppVeyor to maybe not timeout at connecting to GitHub partway through CI: mark get_churn_limit(...), initiate_validator_exit(...), and Validator as 0.6.2
* mark get_attestation_slot(...), AttestationDataAndCustodyBit, and BeaconBlock as 0.6.2
* implement get_churn_limit from 0.6.1; update initiate_validator_exit and get_previous_epoch to 0.6.1; remove obsoleted/non-spec reduce_balance, replaced by decrease_balance; mark BeaconBlock as 0.6.1
* rename get_block_root to get_block_root_at_slot and introduce epoch-oriented get_block_root; implement get_attestation_slot, get_matching_source_attestations, get_matching_target_attestations, get_matching_head_attestations, 0.6.1 get_attesting_indices, get_unslashed_attesting_indices, get_attestation_deltas, process_rewards_and_penalties; rm get_inactivity_penalty
* update Validator and processVoluntaryExits to 0.6.1; rm obsolete inclusion_slots/inclusion_distances
* rm removed activate_validator; mark DepositData, misc values, Gwei values, Randao processing, state caching as 0.6.1; update GENESIS_SLOT to 64, since it doesn't quite yet work at 0
* mark BeaconBlockHeader as 0.6.1; update BeaconBlockBody to 0.6.1; rename WHISTLEBLOWER_REWARD_QUOTIENT to WHISTLEBLOWING_REWARD_QUOTIENT; update slash_validator to 0.6.1
* implement 0.6.2 is_slashable_validator; update processProposerSlashings to 0.6.2; mark state caching as 0.6.2
* mark get_total_active_balance and process_slashings as 0.6.2; update get_base_reward to 0.6.2
* rm prepare_validator_for_withdrawal, process_exit_queue; mark mainnet misc constants as 0.6.2; update process block header to 0.6.2
* address mratsim's code review comment
* Initial move constants to mainnet preset
* Bump fixtures to include shuffling with minimal preset
* Add minimal preset with shuffling test
* Add minimal preset to the full test suite
* use preset() everywhere
Zahary Karadjov
Dustin Brody
Mamy Ratsimbazafy
Jacek Sieka
Mamy Ratsimbazafy
Yuriy Glukhov