Toolchain very slow on Windows machines

[Peter Haas]

Dear Nordic Team,

we are using the adafruit_feather_nrf52840 and nrf52840dk for our prototypes and recently the toolchain around nrf and zephyr has become a problem.

Build times (especially compilation of the device tree according to logs) became very long such that one reload of our cmake project takes up to 15 minutes.

It had worked in reasonable time previously, at some point the toolchain slowed down on 2 individual machines.
This has happened on 2 different machines with 3 different versions of zephyr and the nrf toolchain (v2.6.0, v2.6.1, v2.7.0).

I tested using standalone zephyr for the build which doesn't seem to work trivially, however it does build an image in less than 10 seconds.
Also on a Linux machine I have available, the build times are much shorter.

Is anybody aware of any windows specific problems or problems with dtc.exe that may cause this?

Is there some cache we directory or temporal files we may have missed to clean?

We have been investigating for some time now as it really slows down our development iterations severely.

[Simonr]

Hi Alex

No worries. I have forwarded this to our VS code team and we'll take a look. The things I can think of that you can try: Can you try building the sample within the NCS instead of in your /temp folder, just to see if that makes a difference. Could this be firewall related and only happen on devices on the internal network on your end perhaps? This is just a shot in the dark though. I'll get back to you when I hear from the devs on this.

Best regards,

Simon