More fixes

# Conflicts:
#	codex-rs/core/src/config/mod.rs

codex-rs/Cargo.lock

@@ -1328,6 +1328,7 @@ dependencies = [
  "seccompiler",
  "serde",
  "serde_json",
+ "serde_path_to_error",
  "serde_yaml",
  "serial_test",
  "sha1",

codex-rs/Cargo.toml

@@ -188,6 +188,7 @@ seccompiler = "0.5.0"
 sentry = "0.46.0"
 serde = "1"
 serde_json = "1"
+serde_path_to_error = "0.1"
 serde_with = "3.16"
 serde_yaml = "0.9"
 serial_test = "3.2.0"

codex-rs/core/Cargo.toml

@@ -64,6 +64,7 @@ reqwest = { workspace = true, features = ["json", "stream"] }
 schemars = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
+serde_path_to_error = { workspace = true }
 serde_yaml = { workspace = true }
 sha1 = { workspace = true }
 sha2 = { workspace = true }

codex-rs/core/src/config/mod.rs

@@ -435,11 +435,8 @@ impl ConfigBuilder {
 
         // Note that each layer in ConfigLayerStack should have resolved
         // relative paths to absolute paths based on the parent folder of the
-        // respective config file, so we should be safe to deserialize without
-        // AbsolutePathBufGuard here.
-        let config_toml: ConfigToml = merged_toml
-            .try_into()
-            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
+        // respective config file, so the base-dir guard is not needed here.
+        let config_toml = deserialize_config_toml_with_base(merged_toml, None)?;
         Config::load_config_with_layer_stack(
             config_toml,
             harness_overrides,
@@ -496,7 +493,7 @@ pub async fn load_config_as_toml_with_cli_overrides(
     .await?;
 
     let merged_toml = config_layer_stack.effective_config();
-    let cfg = deserialize_config_toml_with_base(merged_toml, codex_home).map_err(|e| {
+    let cfg = deserialize_config_toml_with_base(merged_toml, Some(codex_home)).map_err(|e| {
         tracing::error!("Failed to deserialize overridden config: {e}");
         e
     })?;
@@ -506,14 +503,13 @@ pub async fn load_config_as_toml_with_cli_overrides(
 
 fn deserialize_config_toml_with_base(
     root_value: TomlValue,
-    config_base_dir: &Path,
+    config_base_dir: Option<&Path>,
 ) -> std::io::Result<ConfigToml> {
     // This guard ensures that any relative paths that is deserialized into an
     // [AbsolutePathBuf] is resolved against `config_base_dir`.
-    let _guard = AbsolutePathBufGuard::new(config_base_dir);
-    root_value
-        .try_into()
-        .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))
+    let _guard = config_base_dir.map(AbsolutePathBufGuard::new);
+    serde_path_to_error::deserialize(root_value)
+        .map_err(|err| std::io::Error::new(std::io::ErrorKind::InvalidData, err.into_inner()))
 }
 
 fn filter_mcp_servers_by_requirements(
@@ -764,12 +760,14 @@ pub struct ConfigToml {
     pub model_auto_compact_token_limit: Option<i64>,
 
     /// Default approval policy for executing commands.
+    #[serde(default)]
     pub approval_policy: Option<AskForApproval>,
 
     #[serde(default)]
     pub shell_environment_policy: ShellEnvironmentPolicyToml,
 
     /// Sandbox mode to use.
+    #[serde(default)]
     pub sandbox_mode: Option<SandboxMode>,
 
     /// Sandbox configuration to apply if `sandbox` is `WorkspaceWrite`.
@@ -848,6 +846,7 @@ pub struct ConfigToml {
 
     /// Optional URI-based file opener. If set, citations to files in the model
     /// output will be hyperlinked using the specified URI scheme.
+    #[serde(default)]
     pub file_opener: Option<UriBasedFileOpener>,
 
     /// Collection of settings that are specific to the TUI.
@@ -861,9 +860,12 @@ pub struct ConfigToml {
     /// Defaults to `false`.
     pub show_raw_agent_reasoning: Option<bool>,
 
+    #[serde(default)]
     pub model_reasoning_effort: Option<ReasoningEffort>,
+    #[serde(default)]
     pub model_reasoning_summary: Option<ReasoningSummary>,
     /// Optional verbosity control for GPT-5 models (Responses API `text.verbosity`).
+    #[serde(default)]
     pub model_verbosity: Option<Verbosity>,
 
     /// Override to force-enable reasoning summaries for the configured model.
@@ -957,6 +959,7 @@ impl From<ConfigToml> for UserSavedConfig {
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema)]
 #[schemars(deny_unknown_fields)]
 pub struct ProjectConfig {
+    #[serde(default)]
     pub trust_level: Option<TrustLevel>,
 }
 
@@ -1749,6 +1752,30 @@ persistence = "none"
         );
     }
 
+    #[tokio::test]
+    async fn invalid_reasoning_effort_is_rejected() -> anyhow::Result<()> {
+        let codex_home = TempDir::new()?;
+        let config_path = codex_home.path().join(CONFIG_TOML_FILE);
+
+        tokio::fs::write(
+            &config_path,
+            r#"
+model_reasoning_effort = "super-high"
+"#,
+        )
+        .await?;
+
+        let config = ConfigBuilder::default()
+            .codex_home(codex_home.path().to_path_buf())
+            .build()
+            .await;
+
+        let error = config.expect_err("invalid enum values should reject config");
+        assert_eq!(error.kind(), std::io::ErrorKind::InvalidData);
+
+        Ok(())
+    }
+
     #[test]
     fn tui_config_missing_notifications_field_defaults_to_enabled() {
         let cfg = r#"
@@ -2363,7 +2390,7 @@ trust_level = "trusted"
             load_config_layers_state(codex_home.path(), Some(cwd), &Vec::new(), overrides).await?;
         let cfg = deserialize_config_toml_with_base(
             config_layer_stack.effective_config(),
-            codex_home.path(),
+            Some(codex_home.path()),
         )
         .map_err(|e| {
             tracing::error!("Failed to deserialize overridden config: {e}");
@@ -2490,7 +2517,7 @@ trust_level = "trusted"
 
         let cfg = deserialize_config_toml_with_base(
             config_layer_stack.effective_config(),
-            codex_home.path(),
+            Some(codex_home.path()),
         )
         .map_err(|e| {
             tracing::error!("Failed to deserialize overridden config: {e}");

codex-rs/core/src/config/profile.rs

@@ -18,10 +18,15 @@ pub struct ConfigProfile {
     /// The key in the `model_providers` map identifying the
     /// [`ModelProviderInfo`] to use.
     pub model_provider: Option<String>,
+    #[serde(default)]
     pub approval_policy: Option<AskForApproval>,
+    #[serde(default)]
     pub sandbox_mode: Option<SandboxMode>,
+    #[serde(default)]
     pub model_reasoning_effort: Option<ReasoningEffort>,
+    #[serde(default)]
     pub model_reasoning_summary: Option<ReasoningSummary>,
+    #[serde(default)]
     pub model_verbosity: Option<Verbosity>,
     pub chatgpt_base_url: Option<String>,
     pub experimental_instructions_file: Option<AbsolutePathBuf>,

codex-rs/core/src/config/types.rs

@@ -352,9 +352,11 @@ pub struct OtelConfigToml {
     pub environment: Option<String>,
 
     /// Optional log exporter
+    #[serde(default)]
     pub exporter: Option<OtelExporterKind>,
 
     /// Optional trace exporter
+    #[serde(default)]
     pub trace_exporter: Option<OtelExporterKind>,
 }
 
@@ -624,6 +626,7 @@ pub enum ShellEnvironmentPolicyInherit {
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, JsonSchema)]
 #[schemars(deny_unknown_fields)]
 pub struct ShellEnvironmentPolicyToml {
+    #[serde(default)]
     pub inherit: Option<ShellEnvironmentPolicyInherit>,
 
     pub ignore_default_excludes: Option<bool>,