\Phalcon\Http\Client\Provider\Curl Throwing Exception with string "curl" as code

[cottton]

See:

incubator/Library/Phalcon/Http/Client/Provider/Curl.php

Line 48 in 08ab1a9

'curl'

Is it me? Tracing this back i see the HttpException extending PHP \Exception - so an int is expected.
What was this ..., 'curl' for?
I think this is in all versions