dune-gen does not support non-deterministic mode

Hi,

It seems that dune-gen (used by stanza 0.2) does not support setting non-deterministic mode:

Lines 35 to 41 in 4942357

    
           line "  run_exn ~packages ~predicates ~prelude_str:[]"; 
        
           line "    ~non_deterministic:false"; 
        
           line "    ~silent_eval:false ~record_backtrace:false"; 
        
           line "    ~syntax:None ~silent:false"; 
        
           line "    ~verbose_findlib:false ~section:None"; 
        
           line "    ~root:None ~force_output:false"; 
        
           line "    ~output:(Some `Stdout)";

If we want MDX_RUN_NON_DETERMINISTIC=1 dune runtest to work, this needs be supported and dune to be adjusted so that it knows about the envvar dependency.

Thanks for the report and the debugging. From the MDX side this should be quite easy to fix.

Does dune pass all the environment options as-is to the binary produced by dune-gen? Or are there other adjustments that are necessary to do?

	line " run_exn ~packages ~predicates ~prelude_str:[]";
	line " ~non_deterministic:false";
	line " ~silent_eval:false ~record_backtrace:false";
	line " ~syntax:None ~silent:false";
	line " ~verbose_findlib:false ~section:None";
	line " ~root:None ~force_output:false";
	line " ~output:(Some `Stdout)";