I cloned the Onion LEDE/OpenWrt cross-compiler yesterday (23 July 2018) from here:
It all built successfully, in an Ubuntu 16.04 VM running on my Mac.
However, like other posters on this thread, I am unable to build the cross-compile example described in the Onion documentation here:
I ran into the same "can't find ugpio/ugpio.h" error that all other posters here on this thread have described.
I see @Pavel-Metrokhin 's tutorial with "A Small but Important Note" about enabling ugpio support in the cross-compiler (via make menuconfig) here:
I've looked at the various options within "make menuconfig" and cannot find one for libugpio anywhere.
Pavel, can you please tell me where, exactly, this libugpio package option is located (within the menuconfig system?) Or - much better - please fix the pre-configured cross-compile environment. And / or fix the documentation. I find it very disconcerting that this problem has been reported to Omega on this forum for more than a year and not been fixed. The example programs should build and run flawlessly.