Verbose print build_helper stdout

Author: jieyouxu

src/build_helper/src/git.rs

@@ -16,6 +16,9 @@ pub fn output_result(cmd: &mut Command) -> Result<String, String> {
         Err(e) => return Err(format!("failed to run command: {:?}: {}", cmd, e)),
     };
     if !output.status.success() {
+        eprintln!("[DEBUG] stdout:\n{}\n\n", String::from_utf8(output.stdout.clone()).unwrap());
+        eprintln!("[DEBUG] stderr:\n{}\n\n", String::from_utf8(output.stderr.clone()).unwrap());
+
         return Err(format!(
             "command did not execute successfully: {:?}\n\
              expected success, got: {}\n{}",
@@ -107,8 +110,10 @@ fn git_upstream_merge_base(
     git_dir: Option<&Path>,
 ) -> Result<String, String> {
     let updated_master = updated_master_branch(config, git_dir)?;
+    eprintln!("updated_master = {:?}", updated_master);
     let mut git = Command::new("git");
     if let Some(git_dir) = git_dir {
+        eprintln!("git_dir = {:?}", git_dir);
         git.current_dir(git_dir);
     }
     Ok(output_result(git.arg("merge-base").arg(&updated_master).arg("HEAD"))?.trim().to_owned())