crash in command line tool

➜  ~  keybase signup
warn: No config file found; tried '/Users/Nicholas/.config/keybase/config.json'
Your email: <I've removed this>
Invitation code (leave blank if you don't have one): <I've removed this>
Your desired username: nick
Your login passphrase: <I've removed this>
Your login passphrase (must be at least 12 letters long): <I've removed this>
Repeat to confirm: <I've removed this>
- run scrypt [==================================] 100%
error: Username 'nick' already registered
Your email: ndesaulniers@mozilla.com
Invitation code (leave blank if you don't have one): <I've removed this>
Your desired username: nickd
Your login passphrase: (<default hidden>)
_http_outgoing.js:333
    throw new Error('"name" and "value" are required for setHeader().');
          ^
Error: "name" and "value" are required for setHeader().
    at ClientRequest.OutgoingMessage.setHeader (_http_outgoing.js:333:11)
    at new ClientRequest (_http_client.js:101:14)
    at Object.exports.request (http.js:49:10)
    at Object.exports.request (https.js:136:15)
    at Request.start (/Users/Nicholas/.nvm/versions/node/v0.12.0/lib/node_modules/keybase/node_modules/request/request.js:583:30)
    at Request.write (/Users/Nicholas/.nvm/versions/node/v0.12.0/lib/node_modules/keybase/node_modules/request/request.js:1232:28)
    at /Users/Nicholas/.nvm/versions/node/v0.12.0/lib/node_modules/keybase/node_modules/request/request.js:403:14
    at process._tickCallback (node.js:355:11)

Reproduce the failure with the keybase signup command, including an already-registered username, then trace the request through node_modules/request/request.js and the Node HTTP client shown in the stack trace. Done means signup handles the rejected username and subsequent input without crashing on setHeader().