I’ve been running into this same issue and found that it’s caused by the build command length exceeding the 32k limit in Windows, this is discussed here: https://community.platformio.org/t/what-is-the-cause-of-this-build-failure/35089
As a desperate temporary workaround I just relocated my .platformio directory from my Windows user directory to c:\.platformio by setting the following environment variable:
PLATFORMIO_CORE_DIR=c:\.platformio
Because the path to this directory is used so many times in the build command this relocation seems to have shortened the command just enough to be under the 32k limit mentioned above. If I get more desperate I’ll shorten the directory name to c:\p
Yes this is a terrible sad hack, but hopefully the esp32 environment will be repackaged in the not too distant future.