The worst type of debugging: Programming an MCU without a Serial Monitor.

Some Context: I've spendt today about 3h+ on getting an attiny 45 to read 3 digital values on 3 pins. So for every test I wanted to make, I needed to put the MCU inside a socket put this socket on a arduino and flash it. Then extract it from the socket and put it on a breadboard for testing.
After getting headaches for nothing making any goddamn sense, I ended up noticing that one input pin is a multiplexed reset pin with the reset having top priority and no way to change it. So whenever this pin should have read a low signal, it got held in reset! FML