dkos depends on KallistOS and its associated newlib being installed in /opt/toolchains/dc
Additionally you will as of current need to compile this branch of dub, just run dub build in its root directory once cloned and branch is changed. Then copy to the bin directory of your liking.
To build this test, compile GDC for sh-elf (see dc-chain scripts in kallistos), then run
dub build --compiler=sh-elf-gdc
You can then optionally run sh-elf-strip on the elf file to shrink its size before you load it in to an emulator or send it to your Dreamcast.
DKOS requires that you are in a UNIX-like environment using a sh-like shell,
the Dreamcast toolchain needs to be installed in /opt/toolchains/dc or dkos will NOT work!