Currently we always request duties for current and next sync period.
As sync periods are quite long (~27 hrs on Mainnet), having access to
the duties so early doesn't help too much. To avoid running into errors
when the BN does not have the duties available around period boundary,
delay requesting them until the current period is close to finish.
`SYNC_COMMITTEE_SUBNET_COUNT` epochs are what the spec says should be
the lookahead timing of starting to subscribe to sync committee gossip.
Reusing the constant here for consistency.
This fixes these warning messages in the first slot of a new period.
```
rocketpool_validator | WRN 2023-09-07 20:19:35.439+00:00 Beacon node has incompatible configuration reason="Epoch value is far from the future;400;getSyncCommitteeDuties(first);invalid-request" node=http://eth2:5052[Nimbus/v23.8.0-872b19-stateofus] node_index=0 node_roles=AGBSDT
rocketpool_validator | WRN 2023-09-07 20:19:35.440+00:00 Unable to get sync committee duties period=889 epoch=227584 reason="Epoch value is far from the future;400;getSyncCommitteeDuties(first);invalid-request" service=duties_service
rocketpool_validator | NOT 2023-09-07 20:19:35.441+00:00 Beacon node is in sync head_slot=7274495 sync_distance=1 is_optimistic=false node=http://eth2:5052[Nimbus/v23.8.0-872b19-stateofus] node_index=0 node_roles=AGBSDT
```
Sync committee duties are performed by the sync committee as determined
by slot + 1. We did it correctly for individual messages, but selected
the incorrect participants for aggregate contributions for the very
first slot per period (roughly 1 per ~27 hrs on Mainnet). The faulty
participants selection code was originally introduced in #2925.
To allow testing https://github.com/ethereum/consensus-specs/issues/3466
add support for selecting fork choice version at launch. This means we
can deploy a different logic when `DENEB_FORK_EPOCH != FAR_FUTURE_EPOCH`
that won't be used on Mainnet.
In `Slot end`, sync duties are reported one slot too late,
because sync committee duties are determined by the next slot
instead of the current one. Address that by taking account of this.
* Add metadata for the Holesky network
* Add copyright banner to the new Nim module
* Working version
* Bump Chronos to fix downloading from Github
* Add checksum check of the downloaded file
* Clean up debugging code and obsolete imports
* optimize epoch transition via get_flag_index_deltas() and get_inactivity_penalty_deltas()
* directly mutate Altair info in {get,update}_flag_and_inactivity_deltas
The `is_next_sync_committee_known` helper allocates a fresh
`SyncCommittee` in the caller and `nimZeroMem`s it on each use.
Use `static` to compare against a compile-time zeroed copy instead.
This also should help reduce stack size far enough to link with Nim 2.0.
Nim 2.0 gets confused when compiling `all_tests`:
```
Error: undeclared identifier: 'maxLen'
candidates (edit distance, scope distance); see '--spellSuggest':
(3, 7): 'Table'
(3, 7): 'len'
(3, 7): 'max'
```
Renaming the generic parameter `U` to `maxLen` fixes this somehow.
It also increases readability to use the same name consistently.
In Nim 2.0, attempting to use `Taskpool.spawn` inside `{.async.}` `proc`
leads to `Error: cannot generate destructor for generic type: Isolated`.
Add an intermediate wrapper `proc` that performs the `spawn` operation
to workaround the problem.
From old interop tests, a mock `eth1BlockHash` was defined in `base`.
To avoid accidental use by Nimbus, move to `tests` and rename it to
`mockEth1BlockHash`.