'make px4_fmu-v4' fails to build after clean install

I am attempting to simply build the firmware for a NuttX / PixHawk board, following the guide here: https://docs.px4.io/master/en/dev_setup/building_px4.html. I have the firmware cloned, the toolchains installed, but the build fails. I should note, when I build for JMavSim, it builds just fine. When I build for an actual NuttX target (I am using PixHawk 4) the build fails. I have tried adding environmental variables (verified with echo) to point to the paths for each compiler… but output is exactly the same, not even showing the path i entered. Here is my output:

My GCC version:

‘find -iname arm-none-eabi*’ output, showing these compilers do in fact exist (altough, seems like a weird place for them)

Any guidance here would be appreciated. I am compiling on Ubuntu 18.04.