Chapel extern reproducer

externtest.chpl

module C {
  extern {
    #include "externtest.h"
    static int foo(int x) { return x + 1; }
    struct mystruct obj;
  }
  proc tryMe() {
    writeln(obj.a);
    return foo(3);
  }
}

writeln(C.tryMe());

//writeln(C.foo(3));
writeln(C.obj.a);

externtest.h

    struct mystruct
    {
    int a;
    int b;
    };