How to create a git repository on swarm?

Question

I'm running geth --testnet on ropsten testnet and attached a swarm node to it. Now I should be able to use mango to host my git repositories on swarm. I installed mango-admin and git-remote-mango nodejs modules.

However, here the documentation somehow stops with specifics. It suggests to run mango-admin create to initialize a repository. But I somehow suspect it defaults to IPFS. And I can not find out how to tell mango to use Swarm instead.

Also, creating a default repository does not work either:

 $ mango-admin create
Initialising...
/usr/lib/node_modules/mango-admin/node_modules/web3/lib/web3/httpprovider.js:87
        throw errors.InvalidResponse(request.responseText);                
        ^

Error: Invalid JSON RPC response: undefined
    at Object.InvalidResponse (/usr/lib/node_modules/mango-admin/node_modules/web3/lib/web3/errors.js:35:16)
    at HttpProvider.send (/usr/lib/node_modules/mango-admin/node_modules/web3/lib/web3/httpprovider.js:87:22)
    at RequestManager.send (/usr/lib/node_modules/mango-admin/node_modules/web3/lib/web3/requestmanager.js:58:32)
    at Eth.get [as coinbase] (/usr/lib/node_modules/mango-admin/node_modules/web3/lib/web3/property.js:107:62)
    at Object.<anonymous> (/usr/lib/node_modules/mango-admin/mango-admin:69:37)
    at Module._compile (module.js:571:32)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
    at Function.Module._load (module.js:439:3)

How to create a git repository on swarm with mango?