GitLab

Goprocess returns a _custom_ context type. Unfortunately, golang has a bunch of
magic type assertions to efficiently handle built-in context types but launches
a new goroutine when deriving a new context from a custom context type.
Otherwise, it has no way to wait on the custom context's channel.

This fix just ensures we only ever have one of goroutines per provide worker by
deriving a (normal) cancelable context up-front and then using that.