Gulp 4: Handling errors without breaking watch

[darsain]

For all types of tasks that:

1. Return a stream.
2. Return a promise.
3. Use a callback.

should we just (as documented):

1. Bind error handlers - doesn't break watch.
2. Reject with error object. - dunno if breaks, haven't used yet.
3. Pass error object as 1st argument - breaks watch.

and let gulp handle it in a future?

Or is there a special error treatment required to not break watchers? If so, please document it for each type of task.

[ilanbiala]

I see this issue come up when I am changing files and node-sass is watching through Gulp, and suddenly gulp.watch errors and closes.

[yocontra]

Closing, this is a duplicate of #359