This appears to be the same issue as this topic. I just did a pio upgrade --dev, but so far no change (it’s taking over an hour). I still see rustc runs on all 4 cores, driving the RasPi3 to the max - so it looks like pio 5.2.4a4 still triggers & needs rust.
Update - to follow up, yep similar error:
ImportError: The version of cryptography does not match the loaded shared object. This can happen if you have multiple copies of cryptography installed in your Python path. Please try creating a new virtual environment to resolve this issue. Loaded python version: 3.1.1, shared object version: b’3.3.2’
I see several versions of cryptography getting built (pulling all its dependencies in, each time) - and then after a while these end up leading the the above error. Lots of heavy rust builds, for sure. I could do a complete PlatformIO reinstall on this RasPi, if that is of any use, but in that case please let me know which exact install method to use.