Hmm - that is strange that it fails for you. Which step fails?
I just blew away my build_utilities directory and rebuilt with the following steps. It worked fine:
>> rm -rf build-utilites/
>> git clone git://git.ti.com/wilink8-wlan/build-utilites.git
>> cd build-utilites/
>> gedit setup-env ( And past my env that I showed previously in the forum chain here )
>> ./build_wl18xx.sh init
>> ./build_wl18xx.sh update R8.7_SP1 ( This will run but eventually fail when it tries to compile everything because TI has a bug... don't worry about the failure )
>> ./build_wl18xx.sh modules
After that I had the modules built:
****** *******
Building modules, stage 2.
MODPOST 7 modules
INSTALL /home/fluke/Desktop/renesas_rza1/wilink_R8.7/build-utilites/src/compat_wireless/compat/compat.ko
INSTALL /home/fluke/Desktop/renesas_rza1/wilink_R8.7/build-utilites/src/compat_wireless/drivers/net/wireless/ti/wl12xx/wl12xx.ko
INSTALL /home/fluke/Desktop/renesas_rza1/wilink_R8.7/build-utilites/src/compat_wireless/drivers/net/wireless/ti/wl18xx/wl18xx.ko
INSTALL /home/fluke/Desktop/renesas_rza1/wilink_R8.7/build-utilites/src/compat_wireless/drivers/net/wireless/ti/wlcore/wlcore.ko
INSTALL /home/fluke/Desktop/renesas_rza1/wilink_R8.7/build-utilites/src/compat_wireless/drivers/net/wireless/ti/wlcore/wlcore_sdio.ko
INSTALL /home/fluke/Desktop/renesas_rza1/wilink_R8.7/build-utilites/src/compat_wireless/net/mac80211/mac80211.ko
INSTALL /home/fluke/Desktop/renesas_rza1/wilink_R8.7/build-utilites/src/compat_wireless/net/wireless/cfg80211.ko
DEPMOD 3.14.28-ltsi
Maybe you are missing something in your Kernel Config. Can you pass that along and I'll try to build with your config?