Darwin make check fail

make check on darwin raise :

core/trival.cc:38:3: error: no viable conversion from 'spot::trival' to 'long'
  assert(v3);
  ^~~~~~~~~~
/usr/include/assert.h:93:23: note: expanded from macro 'assert'
    (__builtin_expect(!(e), 0) ? __assert_rtn(__func__, __FILE__, __LINE__, #e) ...
                      ^~~~
core/trival.cc:39:3: error: no viable conversion from 'spot::trival' to 'long'
  assert(!v2);
  ^~~~~~~~~~~
/usr/include/assert.h:93:23: note: expanded from macro 'assert'
    (__builtin_expect(!(e), 0) ? __assert_rtn(__func__, __FILE__, __LINE__, #e) ...