fix: 增强 GPG 签名失败时的错误提示

src/commands/commit.rs

@@ -350,8 +350,23 @@ impl CommitCommand {
             .output()?;
 
         if !output.status.success() {
+            let stdout = String::from_utf8_lossy(&output.stdout);
             let stderr = String::from_utf8_lossy(&output.stderr);
-            bail!("Failed to amend commit: {}", stderr);
+            
+            let error_msg = if stderr.is_empty() {
+                if stdout.is_empty() {
+                    "GPG signing failed. Please check:\n\
+                     1. GPG signing key is configured (git config --get user.signingkey)\n\
+                     2. GPG agent is running\n\
+                     3. You can sign commits manually (try: git commit --amend -S)".to_string()
+                } else {
+                    stdout.to_string()
+                }
+            } else {
+                stderr.to_string()
+            };
+            
+            bail!("Failed to amend commit: {}", error_msg);
         }
 
         Ok(())

src/git/commit.rs

@@ -174,8 +174,23 @@ impl CommitBuilder {
             .output()?;
         
         if !output.status.success() {
+            let stdout = String::from_utf8_lossy(&output.stdout);
             let stderr = String::from_utf8_lossy(&output.stderr);
-            bail!("Failed to amend commit: {}", stderr);
+            
+            let error_msg = if stderr.is_empty() {
+                if stdout.is_empty() {
+                    "GPG signing failed. Please check:\n\
+                     1. GPG signing key is configured (git config --get user.signingkey)\n\
+                     2. GPG agent is running\n\
+                     3. You can sign commits manually (try: git commit --amend -S)".to_string()
+                } else {
+                    stdout.to_string()
+                }
+            } else {
+                stderr.to_string()
+            };
+            
+            bail!("Failed to amend commit: {}", error_msg);
         }
         
         Ok(())

src/git/mod.rs

@@ -2,6 +2,7 @@ use anyhow::{bail, Context, Result};
 use git2::{Repository, Signature, StatusOptions, Config, Oid, ObjectType};
 use std::path::{Path, PathBuf};
 use std::collections::HashMap;
+use tempfile;
 
 pub mod changelog;
 pub mod commit;
@@ -367,19 +368,29 @@ impl GitRepo {
         let temp_file = tempfile::NamedTempFile::new()?;
         std::fs::write(temp_file.path(), message)?;
 
-        let mut cmd = std::process::Command::new("git");
-        cmd.args(&["commit", "-S", "-F", temp_file.path().to_str().unwrap()])
-            .current_dir(&self.path)
-            .output()?;
-
         let output = std::process::Command::new("git")
             .args(&["commit", "-S", "-F", temp_file.path().to_str().unwrap()])
             .current_dir(&self.path)
             .output()?;
 
         if !output.status.success() {
+            let stdout = String::from_utf8_lossy(&output.stdout);
             let stderr = String::from_utf8_lossy(&output.stderr);
-            bail!("Failed to create signed commit: {}", stderr);
+            
+            let error_msg = if stderr.is_empty() {
+                if stdout.is_empty() {
+                    "GPG signing failed. Please check:\n\
+                     1. GPG signing key is configured (git config --get user.signingkey)\n\
+                     2. GPG agent is running\n\
+                     3. You can sign commits manually (try: git commit -S -m 'test')".to_string()
+                } else {
+                    stdout.to_string()
+                }
+            } else {
+                stderr.to_string()
+            };
+            
+            bail!("Failed to create signed commit: {}", error_msg);
         }
 
         let head = self.repo.head()?;