There is a new arduino system that performs a "deep search" to auto discover libraries-in-libraries. 

If we don't do this then many users will get a lot of complaints because many library authors are making full use of the system. Without auto-discovery compile will fail if a library uses another library that has not been included in the main sketch.ino

That said, experienced users know how to include the libraries they want so Visual Micro has an option to switch this feature off. Uncheck menu item "vMicro>Compiler>Deep Search"

After changing this option the next compile will be a full compile. Subsequent compiles should then be faster.

What effect does switching this option off have on your build times?

Hey,

Thanks for the explanation, makes sense.
I tested: first build now  (38,10 secs)
Second - no code change (5,28 secs)
Both without errors.

Much better indeed (although the previous 2 secs was nice as well).

Hi,

Updates

The main cause of the slowness is if you have upgraded the Arduino IDE above 1.6.9. The AVR tools have been updated in recent releases of Arduino and are much slower than previous releases. Try the zip of arduino 1.6.9 can be downloaded from arduino.cc so you can easily try it out. It affects build times by many 100's of %

+

The Visual Studio version of Visual Micro has huge recent improvements but also new features such as "Parallel build" which makes a big difference. The changes will be reflected to Atmel studio over the next month or so. Having said that if you are not using an ICE debugger then Visual Studio is probably a better IDE.