Work around slow RPCs leading to crash

[linearray]

probably related: #361

When deploying a contract boa will wait for the TX receipt, which states the block the TX is contained in. Afterwards it will reset the state to that block, this involves an eth_getBlockByNumber call: https://github.com/vyperlang/titanoboa/blob/master/boa/vm/fork.py#L194

Problem is, many RPCs don't have that block available on the API in time, boa gets a null result and crashes. A few seconds later the block is available and everything would have worked out. A good example for this behavior is https://sepolia.base.org/. I have seen this with at least two more RPCs in the past few days and, if needed, can find them again.

I worked around this for now by making my network interface artificially slow (introducing 2000ms delay between requests), but I think the fix would be retrying the request (when you know it should be there, like after deploying).

Traceback

  File "/Users/linearray/Documents/vypertest/bin/admin/deploy_erc20.py", line 13, in go
    token    = deployer.deploy(*args)
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/contracts/vyper/vyper_contract.py", line 92, in deploy
    return VyperContract(
        self.compiler_data, *args, filename=self.filename, **kwargs
    )
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/contracts/vyper/vyper_contract.py", line 558, in __init__
    addr = self._run_init(
        *args, value=value, override_address=override_address, gas=gas, sender=sender
    )
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/contracts/vyper/vyper_contract.py", line 591, in _run_init
    address, computation = self.env.deploy(
                           ~~~~~~~~~~~~~~~^
        bytecode=initcode,
        ^^^^^^^^^^^^^^^^^^
    ...<4 lines>...
        sender=sender,
        ^^^^^^^^^^^^^^
    )
    ^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/network.py", line 413, in deploy
    txdata, receipt, trace = self._send_txn(
                             ~~~~~~~~~~~~~~^
        from_=sender, value=value, gas=gas, data=bytecode
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/network.py", line 603, in _send_txn
    self._reset_fork(block_identifier=receipt["blockNumber"])
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/network.py", line 536, in _reset_fork
    self.fork_rpc(self._rpc, reset_traces=False, block_identifier=block_identifier)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/environment.py", line 95, in fork_rpc
    self.evm.fork_rpc(rpc, block_identifier, debug=debug, **kwargs)
    ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/vm/py_evm.py", line 424, in fork_rpc
    self._init_vm(account_db_class)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/vm/py_evm.py", line 397, in _init_vm
    self.patch = VMPatcher(self.vm)
                 ~~~~~~~~~^^^^^^^^^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/vm/py_evm.py", line 63, in __init__
    (self._exc_patchables, vm.state.execution_context),
                           ^^^^^^^^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/eth/vm/base.py", line 141, in state
    self._state = self.build_state(
                  ~~~~~~~~~~~~~~~~^
        self.chaindb.db,
        ^^^^^^^^^^^^^^^^
    ...<2 lines>...
        self.previous_hashes,
        ^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/eth/vm/base.py", line 160, in build_state
    return cls.get_state_class()(db, execution_context, header.state_root)
           ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/eth/vm/state.py", line 65, in __init__
    self._account_db = self.get_account_db_class()(db, state_root)
                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/vm/fork.py", line 174, in __init__
    super().__init__(
    ~~~~~~~~~~~~~~~~^
        caching_rpc, chain_id, block_identifier, *args, **kwargs2
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/linearray/Documents/vypertest/.venv/lib/python3.14/site-packages/boa/vm/fork.py", line 197, in __init__
    self._block_number = to_int(self._block_info["number"])
                                ~~~~~~~~~~~~~~~~^^^^^^^^^^
TypeError: 'NoneType' object is not subscriptable