The test repo did not work for me.
i got this error message when running
python build.py:
cl : Command line error D8021 : invalid numeric argument ‘/Wno-expansion-to-defined’
ninja: build stopped: subcommand failed.
using windows.
In advance, thanks for the help 
Hi @simon-cmyk,
I am unable to replicate the issue, as I get stuck on collect2.exe: fatal error: CreateProcess: No such file or directory. I have filed your issue in the repo: cl : Command line error D8021 : invalid numeric argument ‘/Wno-expansion-to-defined’ · Issue #10 · edgeimpulse/voice-activated-microbit · GitHub.
Could you try building the application on a Mac/Linux machine or using the Docker method?