I seem to be running into problems when trying to interact with the v1 API, which in turn seems to cause the Ember front-end to display a "An error occurred." message.

It looks like all requests on the v1 API seem to be failing - both trying to fetch http://127.0.0.1:6565/v1/xxx and k6 commands that rely on the endpoints (for example "$ k6 stats") raise a panic on the lingering k6 instance. My scenario would be:

1) launching a k6 run for a script, pausing it when completes via the
lingering flag:
$ docker run --rm --net=host -v /tmp/scripts/localhost.js:/myscript.js loadimpact/k6:latest run -u 1 -d 1s -l /myscript.js
(execution is fine - http requests are made, etc and pauses when the specified amount of time passed)

2) launching a request for the v1 api, via HTTP or command
2.1) launch another command on another shell (ex. stats)
-----
$ docker run --rm --net=host  loadimpact/k6:latest stats
time="2016-12-17T15:26:47Z" level=error msg=Error error="unexpected end of JSON input"
unexpected end of JSON input

2.2) panic on the other shell with the k6 run
2016/12/17 15:26:47 [Recovery] panic recovered:
GET /v1/metrics HTTP/1.1
Host: 127.0.0.1:6565
Accept-Encoding: gzip
User-Agent: Go-http-client/1.1


interface conversion: interface {} is nil, not *lib.Engine
/usr/local/go/src/runtime/panic.go:458 (0x431883)
    gopanic: reflectcall(nil, unsafe.Pointer(d.fn), deferArgs(d), uint32(d.siz), uint32(d.siz))
/usr/local/go/src/runtime/iface.go:201 (0x414c2f)
    panicdottype: panic(&TypeAssertionError{iface.string(), haveString, want.string(), ""})
/go/src/github.com/loadimpact/k6/api/common/context.go:37 (0x59151e)
    GetEngine: return ctx.Value(ctxKeyEngine).(*lib.Engine)
(...)