There is a very interesting bug in Node.js which doesn't detect (correctly, may I add) if a specific port is bound if there is interlaced networking.
I first saw this on this bug and I decided to replicate it; it works, for some reason. You can visit the link and see how to do it yourself.
Since Node uses libuv at its event-based architecture, I wanted to see what exactly
is causing this error; for that, I created a simple HTTP server in C using libuv.
If you're on macOS, fantastic news! Just git clone and git submodule update --recursive --remote.
Then run make and you'll get the server binary. Execute it!
I have no clue. :|