UAR crashes when called in WL

Trying

noinline
int foo( int a, int b)
{   return a; }

int main()
{
   return _sel_VxA_( [0], { [i] -> foo(i,i) | [i] < [10] });
}

crashes in code generation with

** 21: Generating Code ...
  **** Tag preparation ...
  **** Creating intermediate code macros ...
TRAVERSE ERROR: node of type 0:undefined found where 58:N_avis was expected!

when using debug compiler -v4