However, just over a week ago, a new version was added to the ESP32 bits, version 2.0.4, and this no longer works with the specific chip type I am using. Hence I need to be able to configure my arduino-cli build to continue to use version 2.0.3 (which is still listed there in package_esp32_index.json), rather than always updating to and using the latest version, which is what it seems to do naturally.
How do I tell it to use a specific version of the platform stuff?
[EDITED]: found where to put that! Apologies, I had to just unpack the bits of our automated test system which emit these commands, I found the bit where it does: