Core bug

[niftylettuce]

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at ServerResponse.setHeader (_http_outgoing.js:485:11)
    at Cookies.set (/Users/foo/Projects/forwardemail.net/node_modules/cookies/index.js:116:13)
    at Object.set (/Users/jack/Projects/forwardemail.net/node_modules/koa-generic-session/lib/session.js:462:20)
    at /Users/foo/Projects/forwardemail.net/node_modules/koa-generic-session/lib/session.js:189:28
    at Generator.next (<anonymous>)
    at step (/Users/foo/Projects/forwardemail.net/node_modules/koa-generic-session/lib/session.js:3:191)
    at /Users/foo/Projects/forwardemail.net/node_modules/koa-generic-session/lib/session.js:3:361