wire up adapter macros to stderr stream print

src/lib.rs

@@ -52,6 +52,7 @@ pub unsafe extern "C" fn main(
     args_len: usize,
     preopens: PreopenList,
 ) -> u32 {
+    set_stderr_stream(stderr);
     State::with_mut(|state| {
         // Initialization of `State` automatically fills in some dummy
         // structures for fds 0, 1, and 2. Overwrite the stdin/stdout slots of 0
@@ -2406,6 +2407,8 @@ extern "C" {
     fn set_state_ptr(state: *const RefCell<State>);
     fn get_allocation_state() -> AllocationState;
     fn set_allocation_state(state: AllocationState);
+    fn get_stderr_stream() -> Fd;
+    fn set_stderr_stream(fd: Fd);
 }
 
 impl State {

src/macros.rs

@@ -2,12 +2,10 @@
 //!
 //! We're avoiding static initializers, so we can't have things like string
 //! literals. Replace the standard assert macros with simpler implementations.
-
-// TODO: Wire this up to stderr.
 #[allow(dead_code)]
 #[doc(hidden)]
 pub fn print(message: &[u8]) {
-    crate::bindings::stderr::print(message)
+    let _ = unsafe { crate::bindings::streams::write(crate::get_stderr_stream(), message) };
 }
 
 /// A minimal `eprint` for debugging.