Total available RAM size on ESP32 and the meaning of `ESP_STACK_SIZE`?

I ran into the same problem when trying to build a board without the BLUETOOTH module. To fix it, you need to edit the file make/family/ESP32.make and add this line after line 10:
SOURCES += targets/esp32/jshardwareESP32.c.

BTW: Removing Bluetooth also reduces power consumption by around 40ma.