I have an Arduino IDE 1.8.5 setup (installed from the ZIP file) which I use to work exclusively with a single board. Every time the IDE is restarted, the first compilation takes much longer than subsequent ones. Apparently, the reason is that Arduino IDE rebuilds the core library:
Archiving built core (caching) in: C:\Users\User\AppData\Local\Temp\arduino_cache_976772\core\core_arduino_avr_mega_cpu_atmega2560_82177ffe36573ad451e992f583fff1d1.a
Is there a way to prevent that and make the IDE keep the cached core library across restarts? I have the "Aggressively cache compiled core" option checked, but it doesn't seem to help.