Print out stderr if CLI test fails

crates/cli/tests/cli_run.rs

@@ -233,7 +233,13 @@ mod cli_run {
                 );
             }
 
-            assert!(out.status.success());
+            if !out.status.success() {
+                // We don't need stdout, Cargo prints it for us.
+                panic!(
+                    "Example program exited with status {:?}\nstderr was:\n{:#?}",
+                    out.status, out.stderr
+                );
+            }
         }
     }
 

examples/parser/platform/host.c

@@ -136,7 +136,7 @@ int main() {
   }
 
   // Write to stdout
-  if (write(1, str_bytes, str_len) >= 0) {
+  if (write(STDOUT_FILENO, str_bytes, str_len) >= 0) {
     // Writing succeeded!
     return 0;
   } else {