make it work with musl (the _nox target does not link the screen module that wouldn't build)

crsn_stdio/src/lib.rs

@@ -9,6 +9,7 @@ use crsn::sexp::SourcePosition;
 use std::convert::TryFrom;
 use std::io;
 use crsn::asm::instr::cond::Flag;
+use std::fmt;
 
 mod console {
     use std::{io};
@@ -98,7 +99,7 @@ mod console {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct StdioOps {
     old_tio: Option<libc::termios>,
     hdl_stdin : Value,
@@ -107,6 +108,17 @@ pub struct StdioOps {
     hdl_stdout_raw : Value,
 }
 
+impl fmt::Debug for StdioOps {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("StdioOps")
+            .field("hdl_stdin", &format_args!("0x{:08x}", self.hdl_stdin))
+            .field("hdl_stdin_raw", &format_args!("0x{:08x}", self.hdl_stdin_raw))
+            .field("hdl_stdout", &format_args!("0x{:08x}", self.hdl_stdout))
+            .field("hdl_stdout_raw", &format_args!("0x{:08x}", self.hdl_stdout_raw))
+            .finish()
+    }
+}
+
 impl StdioOps {
     pub fn new() -> Box<dyn CrsnExtension> {
         Box::new(Self {