I've faced an issue with flashing some stm32 microcontrollers, built-in utility stm32flash throws segmentation fault error (11) when trying to flash these controllers with a memory offset more that some magic value (I suppose more that flash sector size). I've tried to compile this utility from sources and it works good. So I suppose this utility has been fixed not a long ago. And the ststm32 should be updated with this new version of utility to provide an ability to flash these devices with memory offest (for example to create main firmware+bootloader configuration).
The issue can be faced while flashing some of stm32f103 high density chips with 256kb of memory. Also can be faced when flashing stm32 clones simulating these device IDs.
I use Macos Big Sur
Platformio Core 6.1.1·Home 3.4.2
STSTM32 15.3.0