were you able to build in the end?
running Setup.sh does not generate make file for me.
Running GenerateProjectFiles line by line only led me to the same error when I tried to run:
dotnet msbuild /restore /target:build /property:Configuration=Development /nologo $BASE_PATH/…/…/…/Source/Programs/UnrealBuildTool/UnrealBuildTool.csproj /verbosity:quiet