Just run
nixFlakes run . -- <vmt-file>
The file default.nix contains a complete build description that
works with the Nix package
manager.
After cloning the repo, you can do:
nix-build .
and after the build completes, you can run euforia like so:
./result/bin/euforia <vmt-file>
You can find some example VMT files in ./examples.
If you like, setup.sh can give you a general idea of how to build euforia,
but it might be out of sync with the nix build. The nix build is in
euforia.nix.