From 53601b5c71f8e39b7ab051970473a6a105736397 Mon Sep 17 00:00:00 2001
From: Ryo Yamashita <qryxip@gmail.com>
Date: Wed, 6 Sep 2023 01:43:20 +0900
Subject: [PATCH] =?UTF-8?q?C=20API=E3=81=AE=E3=82=A8=E3=83=A9=E3=83=BC?=
 =?UTF-8?q?=E8=A1=A8=E7=A4=BA=E3=82=92`tracing::error!`=E3=81=AB=E3=81=99?=
 =?UTF-8?q?=E3=82=8B=20(#600)?=
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---
 Cargo.lock                                |  2 ++
 crates/voicevox_core_c_api/Cargo.toml     |  2 ++
 crates/voicevox_core_c_api/src/helpers.rs | 10 +++++++---
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 6f304e58c..871df23ea 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4198,6 +4198,7 @@ dependencies = [
  "duct",
  "easy-ext",
  "inventory",
+ "itertools",
  "libc",
  "libloading",
  "libtest-mimic",
@@ -4215,6 +4216,7 @@ dependencies = [
  "thiserror",
  "tokio",
  "toml 0.7.2",
+ "tracing",
  "tracing-subscriber",
  "typetag",
  "uuid",
diff --git a/crates/voicevox_core_c_api/Cargo.toml b/crates/voicevox_core_c_api/Cargo.toml
index 9264fc183..58db5c0ec 100644
--- a/crates/voicevox_core_c_api/Cargo.toml
+++ b/crates/voicevox_core_c_api/Cargo.toml
@@ -18,11 +18,13 @@ directml = ["voicevox_core/directml"]
 [dependencies]
 cstr = "0.2.11"
 derive-getters.workspace = true
+itertools.workspace = true
 libc = "0.2.134"
 once_cell.workspace = true
 serde_json.workspace = true
 thiserror.workspace = true
 tokio.workspace = true
+tracing.workspace = true
 tracing-subscriber.workspace = true
 uuid.workspace = true
 voicevox_core.workspace = true
diff --git a/crates/voicevox_core_c_api/src/helpers.rs b/crates/voicevox_core_c_api/src/helpers.rs
index 0b889e60c..7cc8c1df3 100644
--- a/crates/voicevox_core_c_api/src/helpers.rs
+++ b/crates/voicevox_core_c_api/src/helpers.rs
@@ -1,7 +1,8 @@
-use std::fmt::Debug;
+use std::{error::Error as _, fmt::Debug, iter};
 use voicevox_core::UserDictWord;
 
 use thiserror::Error;
+use tracing::error;
 
 use super::*;
 use voicevox_core::AccentPhraseModel;
@@ -13,8 +14,11 @@ pub(crate) fn into_result_code_with_error(result: CApiResult<()>) -> VoicevoxRes
     return into_result_code(result);
 
     fn display_error(err: &CApiError) {
-        eprintln!("Error(Display): {err}");
-        eprintln!("Error(Debug): {err:#?}");
+        itertools::chain(
+            [err.to_string()],
+            iter::successors(err.source(), |&e| e.source()).map(|e| format!("Caused by: {e}")),
+        )
+        .for_each(|msg| error!("{msg}"));
     }
 
     fn into_result_code(result: CApiResult<()>) -> VoicevoxResultCode {