Build errors with -DGC_DEBUG -DMRB_GC_STRESS

[yyamano]

I got the following compile errors with -DGC_DEBUG -DMRB_GC_STRESS. The problem is that debug log is written to stdout. Are there any reasons to not use stderr?

CC    build/host/mrblib/mrblib.c -> build/host/mrblib/mrblib.o
/home/vagrant/mruby/build/host/mrblib/mrblib.c:12:10: error: expected declaration specifiers or '...' before numeric constant
 obj_free(0x2139140,tt=16)
          ^
/home/vagrant/mruby/build/host/mrblib/mrblib.c:12:20: error: unknown type name 'tt'
 obj_free(0x2139140,tt=16)
                    ^
/home/vagrant/mruby/build/host/mrblib/mrblib.c:12:10: error: expected declaration specifiers or '...' before numeric constant
 obj_free(0x2139140,tt=16)
          ^
/home/vagrant/mruby/build/host/mrblib/mrblib.c:12:20: error: unknown type name 'tt'
 obj_free(0x2139140,tt=16)
                    ^
rake aborted!

/home/vagrant/mruby/build/host/mrblib/mrblib.c

      6 void
      7 mrb_init_mrblib(mrb_state *mrb)
      8 {
      9   mrb_load_irep(mrb, mrblib_irep);                                                                                        
     10 }
     11
     12 obj_free(0x2139140,tt=16)
     13 obj_free(0x2139140,tt=16)
     14 obj_free(0x2139140,tt=16)
     15 obj_free(0x2139140,tt=16)

https://github.com/mruby/mruby/blob/master/src/gc.c#L704

DEBUG(printf("obj_free(%p,tt=%d)\n",obj,obj->tt));

[take-cheeze]

Seems like in mrbc the debug message is printed to generated file.
You should use those flag in non-host(or default) MRuby::Build.