reduce import diff and always print stdout in tests

cc-test/build.rs

@@ -1,6 +1,7 @@
+use std::env;
+use std::fs;
 use std::path::{Path, PathBuf};
 use std::process::Command;
-use std::{env, fs};
 
 fn main() {
     // if we are being executed from a `fork_run_action` call (i.e. this is a

cc-test/tests/output.rs

@@ -38,5 +38,7 @@ fn load_output(action: &str) -> (String, String) {
     let action_dir = PathBuf::from(env!("OUT_DIR")).join(action);
     let stdout = fs::read_to_string(action_dir.join("stdout")).unwrap();
     let stderr = fs::read_to_string(action_dir.join("stderr")).unwrap();
+    println!("compile stdout: {:?}", action, stdout);
+    println!("compile stderr: {:?}", action, stderr);
     (stdout, stderr)
 }