The ports/esp32s2 build setup is a rather involved process. Please read the README.md in that directory. It has instructions that also refer to further instructions in the ESP-IDF documentation.
On MacOS, you will need to install cmake:
brew install cmake
On Linux you probably need to install ninja-build and cmake.
sudo apt install ninja-build cmake
The ESP-IDF expects there to be a python command which runs python3. On Ubuntu, there is no plain python by default, so install this simple package which links python to python3.
sudo apt install python-is-python3
Once you have the prerequisites installed, change to the ports/esp32s2 directory, and run the install.sh script. You only need to do this once.
cd circuitpython/ports/esp32s2 esp-idf/install.sh
After this, in each fresh terminal window in which you are doing builds, you need to use esp-idf/export.sh in order to set up the correct PATH and other environment variables.
# Do this in each new terminal. cd circuitpython/ports/esp32s2 source esp-idf/export.sh
Now you can build, for example:
make BOARD=adafruit_magtag_2.9_grayscale
