running dry-run with harmony fails

[joequant]

I think there is an incomptability with in process fork blockchain returns

/usr/lib/node_modules/truffle/build/webpack:/node_modules/ganache-core/lib/forking/forked_blockchain.js:375                                                   
    block.header.difficulty = utils.toBuffer("0x" + json.totalDifficulty.toString(16)); // BigNumber                                                          
^                                                                                                                                                             
TypeError: Cannot read properties of undefined (reading 'toString')                                                                                           
    at Object.callback (/usr/lib/node_modules/truffle/build/webpack:/node_modules/ganache-core/lib/forking/forked_blockchain.js:375:1)                        
    at sendTxCallback (/usr/lib/node_modules/truffle/build/webpack:/node_modules/ganache-core/node_modules/web3-core-method/src/index.js:664:1)               
    at onJsonrpcResult (/usr/lib/node_modules/truffle/build/webpack:/node_modules/ganache-core/node_modules/web3-core-requestmanager/src/index.js:179:1)      
    at /home/joe/local2/bench/git/tribute-harmony/tribute-contracts/node_modules/@trufflesuite/web3-provider-engine/index.js:240:9                            
    at /home/joe/local2/bench/git/tribute-harmony/tribute-contracts/node_modules/async/internal/once.js:12:16                                                 
    at replenish (/home/joe/local2/bench/git/tribute-harmony/tribute-contracts/node_modules/async/internal/eachOfLimit.js:61:25)                              
    at /home/joe/local2/bench/git/tribute-harmony/tribute-contracts/node_modules/async/internal/eachOfLimit.js:71:9                                           
    at eachLimit (/home/joe/local2/bench/git/tribute-harmony/tribute-contracts/node_modules/async/eachLimit.js:43:36)
    at /home/joe/local2/bench/git/tribute-harmony/tribute-contracts/node_modules/async/internal/doLimit.js:9:16
    at end (/home/joe/local2/bench/git/tribute-harmony/tribute-contracts/node_modules/@trufflesuite/web3-provider-engine/index.js:217:5)
    at WebsocketSubprovider._handleSocketMessage (/home/joe/local2/bench/git/tribute-harmony/tribute-contracts/node_modules/@trufflesuite/web3-provider-engine/subproviders/websocket.js:123:5)

This is failing at

  await bankFactory.createBank(maxExternalTokens);
  let pastEvent;
  while (pastEvent === undefined) {
    let pastEvents = await bankFactory.getPastEvents();  <====
    pastEvent = pastEvents[0];
  }