This could perhaps be handled by just swallowing errors in the constructor (as is done for Unix sockets, for example) and trying to connect in emit() if there is no connection.

Not sure I want to go down the caching route - it complicates things for what is a rare use case, plus raises the question of allowing configurable timeouts for the cache, etc.

This seems a rare use case, so I have things that have a higher priority on my list of things to do, but I'll certainly review a patch to address this.