Etheno fails to run with --geth and genesis.json

[nettrino]

Getting the following when running etheno --geth -j genesis.json

Traceback (most recent call last):
  File "/Users/nettrino/venvs/etheno/bin/etheno", line 8, in <module>
    sys.exit(main())
  File "/Users/nettrino/venvs/etheno/lib/python3.9/site-packages/etheno/__main__.py", line 204, in main
    private_key=decode_value(pkey)))
  File "/Users/nettrino/venvs/etheno/lib/python3.9/site-packages/etheno/utils.py", line 46, in decode_value
    elif v.startswith('0x') or (frozenset(['a', 'b', 'c', 'd', 'e', 'f']) & frozenset(v)):
AttributeError: 'NoneType' object has no attribute 'startswith

The genesis.json file used is

{
"config":{
   "chainId": 1337,
    "homesteadBlock": 0,
    "eip150Block": 0,
    "eip150Hash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "eip155Block": 0,
    "eip158Block": 0,
    "byzantiumBlock": 0,
    "constantinopleBlock": 0
},
 "alloc": {
        "0x72f52e17469e13b9D0D3aAA5922A597eFCdaF27e": {
            "balance": "100000000000000000000"
        }
},
"coinbase" : "0x0000000000000000000000000000000000000000",
"difficulty" : "0x20000",
"extraData" : "",
"gasPrice": "0xc000310480",
"gasFeeCap": "0xc000083d40",
"gasTipCap": "0xc0003c00b0",
"gasLimit" : "0x4bb14a0",
"nonce" : "0x0000000000000042",
"mixhash" :
"0x0000000000000000000000000000000000000000000000000000000000000000",
"parentHash" :
"0x0000000000000000000000000000000000000000000000000000000000000000",
"timestamp" : "0x00"
}