Well but it definitely doesn’t compile correctly with that version.
Just going by the date of the project, I tried the last platform-espressif32 version that was using the Arduino-ESP32 1.0.6 core, which per releases is 3.5.0, and it compiled immediately. So just set
platform = espressif32@3.5.0
instead of
platform = espressif32
in both esp32 environments.
On the current versions, the RTTI (runtime type information) flags do not seem to be correctly processed, so that build_unflags = [..] -fno-rtti doesn’t have the desired effect. There were previously some discussion on this in Force RTTI from library?. After a short round of trying though, I was unable to get that to compile with the extra_script.
For stability reasons, you’ll always want to pin the platform version like shown above.