Oh plenty of times. The biggest problem is that when I'm reinventing the wheel, I don't want my design to be constrained by existing axles, so naturally I have

Oh plenty of times. The biggest problem is that when I'm reinventing the wheel, I don't want my design to be constrained by existing axles, so naturally I have to reinvent those too, and so on and so forth. At this point I have this tangled web of custom IoT devices (motion sensors, lightbulbs, smart plugs, thermostat, etc) that I build and write all the firmware and orchestration software for. I have them all do autoconf and service discovery via mDNS, and the state of DNS parsing libraries in that space isn't amazing. I've run into multiple libraries now that actually error out or crash on completely valid and in-the-wild edge cases (usually involving some combination of message compression and zero-length fields), and it's often easier to just write a new parser that only bothers to handle the parts I care about rather than fixing a much larger parser so it doesn't crash.