The current ebuild (sys-apps/i2c-tools-4.1-r1.ebuild) has a line: rm -rf "${D}"/usr/include || die # part of linux-headers This seems to be a hold-over from when i2c-tools was installing header files that conflicted with header files provided by the kernel. I manually compiled i2c-tools and did a PREFIX install to see what was being installed. The only file in the include subdirectory was i2c/smbus.h. This file does not conflict with anything provided by the kernel, so I would suggest removing the `rm` now. (I ran into this because I was trying to compile another opensource project that was using libi2c from i2c-tools and couldn't find this header file)
I can confirm that it is safe to remove the line from the ebuild. I also needed the include file i2c/smbus.h. After deleting the line from the ebuild and emering i2c-tools, I was able to successfully compile another tool that depends on the include file.
Fixed in 4.2, sorry for really long delay :/
