Not sure that this is the right place to ask. I use platformio 4.3.4 with the arduino framework. In various sketches that I looked at, it is implied that loop() is called within an endless loop so ...
I have custom STM32F030C8T6 based board and when I use HSI or nothing change at sketch level everything works as expected. But when I want to use HSE and use SystemClock_Config(void) at sketch level, ...