Build firmware not working.

After I runned this (official) code:

# Get the Espruino source code
git clone https://github.com/espruino/Espruino.git­
cd Espruino
# Download and set up the toolchain ('source' is important here)
source scripts/provision.sh ESP32
# Clean and rebuild
make clean && BOARD=ESP32 make

no espruino_esp32.bin was created.
The terminal last output is:

cc1: warning: unrecognized command line option '-Wno-expansion-to-defined'
make: *** wait: No child processes. Stop.

Jonas