Show paths of config files when configurations contain errors

This addresses issue #3317, where as discussed we want to show the paths to
configuration files if they contain errors, to make it easier for the user to
locate them.

CHANGELOG.md

@@ -17,6 +17,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### New features
 
+* Show paths to config files when configuration errors occur
+
 ### Fixed bugs
 
 ## [0.18.0] - 2024-06-05

cli/src/cli_util.rs

@@ -2828,11 +2828,25 @@ impl CliRunner {
         let maybe_cwd_workspace_loader = WorkspaceLoader::init(find_workspace_dir(&cwd))
             .map_err(|err| map_workspace_load_error(err, None));
         layered_configs.read_user_config()?;
+        let mut repo_config_path = None;
         if let Ok(loader) = &maybe_cwd_workspace_loader {
             layered_configs.read_repo_config(loader.repo_path())?;
+            repo_config_path = Some(layered_configs.repo_config_path(loader.repo_path()));
         }
         let config = layered_configs.merge();
-        ui.reset(&config)?;
+        if let Err(e) = ui.reset(&config) {
+            let user_config_path = layered_configs.user_config_path()?;
+            let paths = [repo_config_path, user_config_path]
+                .into_iter()
+                .filter_map(|path| path.map(|x| format!("- {}", x.display())))
+                .join("\n");
+            writeln!(
+                ui.warning_default(),
+                "{}\nCheck the following config files:\n{}",
+                e.error.to_string(),
+                paths
+            )?;
+        }
 
         let string_args = expand_args(ui, &self.app, env::args_os(), &config)?;
         let (matches, args) = parse_args(

cli/src/config.rs

@@ -228,12 +228,20 @@ impl LayeredConfigs {
         Ok(())
     }
 
+    pub fn user_config_path(&self) -> Result<Option<PathBuf>, ConfigError> {
+        existing_config_path()
+    }
+
     #[instrument]
     pub fn read_repo_config(&mut self, repo_path: &Path) -> Result<(), ConfigError> {
-        self.repo = Some(read_config_file(&repo_path.join("config.toml"))?);
+        self.repo = Some(read_config_file(&self.repo_config_path(repo_path))?);
         Ok(())
     }
 
+    pub fn repo_config_path(&self, repo_path: &Path) -> PathBuf {
+        repo_path.join("config.toml")
+    }
+
     pub fn parse_config_args(&mut self, toml_strs: &[String]) -> Result<(), ConfigError> {
         let config = toml_strs
             .iter()