Error al crear CustomGenesis

Estoy intentando implementar en mi red de prueba Ethereum local. Mi nueva dirección de red de prueba necesita un saldo. Así que trato de crear un archivo de Génesis:

geth init
Fatal: Must supply path to genesis JSON file
~/geth init CustomGenesis.json
Fatal: invalid genesis file: json: cannot unmarshal hex string of odd length into Go struct field Genesis.extraData of type hexutil.Bytes
~/geth init CustomGenesis2.json
Fatal: Failed to read genesis file: open CustomGenesis2.json: no such file or directory
~/e CustomGenesis.json
~/cat CustomGenesis.json
{
    "nonce": "0x0000000000000042",
    "timestamp": "0x0",
    "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "extraData": "0x0",
    "gasLimit": "0x8000000",
    "difficulty": "0x400",
    "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "coinbase": "0x3333333333333333333333333333333333333333",
    "alloc": {
     "0x9370855ace244dc18fba024988046dde0d9f8ad8": {
      "balance": "1000000000000000000000"
      }
    }
}

¿Qué pasa con mi CustomGenesis.json?

EDITAR:

Intenté ejecutar los comandos desde https://github.com/ethereum/go-ethereum/wiki/Private-network

CustomGénesis.json:

{
    "config": {
        "chainId": 15,
        "homesteadBlock": 0,
        "eip155Block": 0,
        "eip158Block": 0
    },
    "difficulty": "200000000",
    "gasLimit": "2100000",
     "alloc": {
     "0x9370855ace244dc18fba024988046dde0d9f8ad8": {
      "balance": "1000000000000000000000"
      }
    }
}

Para crear una base de datos que use este bloque de génesis, ejecute el siguiente comando. Esto importará y establecerá el bloque de génesis canónico para su cadena.

geth --datadir ruta/a/personalizado/datos/carpeta init genesis.json

Las ejecuciones futuras de geth en este directorio de datos usarán el bloque de génesis que ha definido.

geth --datadir ruta/a/personalizado/datos/carpeta --networkid 15

Así que ejecuto lo anterior con

geth --rpc --datadir path/to/custom/data/folder --networkid 15
WARN [03-05|19:33:23] No etherbase set and no accounts found as default
INFO [03-05|19:33:23] Starting peer-to-peer node               instance=Geth/v1.7.2-stable/darwin-amd64/go1.9.2
INFO [03-05|19:33:23] Allocated cache and file handles         database=/Users/quantum/cc/geth/path/to/custom/data/folder/geth/chaindata cache=128 handles=1024
INFO [03-05|19:33:23] Initialised chain configuration          config="{ChainID: 1 Homestead: 1150000 DAO: 1920000 DAOSupport: true EIP150: 2463000 EIP155: 2675000 EIP158: 2675000 Byzantium: 4370000 Engine: ethash}"
INFO [03-05|19:33:23] Disk storage enabled for ethash caches   dir=/Users/quantum/cc/geth/path/to/custom/data/folder/geth/ethash count=3
INFO [03-05|19:33:23] Disk storage enabled for ethash DAGs     dir=/Users/quantum/.ethash                                        count=2
INFO [03-05|19:33:23] Initialising Ethereum protocol           versions="[63 62]" network=15
INFO [03-05|19:33:23] Loaded most recent local header          number=0 hash=d4e567…cb8fa3 td=17179869184
INFO [03-05|19:33:23] Loaded most recent local full block      number=0 hash=d4e567…cb8fa3 td=17179869184
INFO [03-05|19:33:23] Loaded most recent local fast block      number=0 hash=d4e567…cb8fa3 td=17179869184
INFO [03-05|19:33:23] Loaded local transaction journal         transactions=0 dropped=0
INFO [03-05|19:33:23] Regenerated local transaction journal    transactions=0 accounts=0
INFO [03-05|19:33:23] Starting P2P networking
INFO [03-05|19:33:25] UDP listener up                          self=enode://cd3f867d2e6e268ab27e555e255097bb96f1f61381dcce74c90a11ee2f960e8542955764a14c7e96e5002b10eb2cc74badf29f974d4d3b61b936e2be36bfe7b6@[::]:30303
INFO [03-05|19:33:25] RLPx listener up                         self=enode://cd3f867d2e6e268ab27e555e255097bb96f1f61381dcce74c90a11ee2f960e8542955764a14c7e96e5002b10eb2cc74badf29f974d4d3b61b936e2be36bfe7b6@[::]:30303
INFO [03-05|19:33:25] IPC endpoint opened: /Users/quantum/cc/geth/path/to/custom/data/folder/geth.ipc
INFO [03-05|19:33:25] HTTP endpoint opened: http://127.0.0.1:8545

luego en un caparazón nuevo,

geth attach
Fatal: Unable to attach to remote geth: dial unix /Users/quantum/Library/Ethereum/geth.ipc: connect: no such file or directory

así que ahora no puedo conectarme a mi red de prueba.

geth version
Geth
Version: 1.7.2-stable
Architecture: amd64
Protocol Versions: [63 62]
Network Id: 1
Go Version: go1.9.2


Operating System: darwin
GOPATH=/Users/quantum/code/go
GOROOT=/usr/local/Cellar/go/1.9.2/libexec