feat(doctor): report editor and pager environment (#27081)

## Background

This was prompted by
[#26858](https://github.com/openai/codex/issues/26858), where the
attached doctor report did not include the editor selection and I had to
[ask which editor was in
use](https://github.com/openai/codex/issues/26858#issuecomment-4653829891)
before investigating the external-editor newline issue. Capturing these
variables in doctor makes that context available up front in future
reports.

`codex doctor` is intended to capture enough local context to diagnose
startup and terminal behavior, but it did not report the environment
variables that select an external editor or configure command pagers.

The TUI [prefers `VISUAL` over
`EDITOR`](https://github.com/openai/codex/blob/56554904babcaacf4444a2cc90716880837dff7c/codex-rs/tui/src/external_editor.rs#L31-L38),
so missing or unexpected values can explain why the external-editor
shortcut fails or launches the wrong command. Pager values are also
useful inherited-shell context even though [unified exec normalizes its
effective pager variables to
`cat`](https://github.com/openai/codex/blob/56554904babcaacf4444a2cc90716880837dff7c/codex-rs/core/src/unified_exec/process_manager.rs#L60-L70).

These variables can contain arbitrary command arguments or inline
environment assignments. The human report is local, but `codex doctor
--json` may be attached to feedback, so the machine-readable report
should not include their raw contents.

## What Changed

- Report `VISUAL` and `EDITOR` in the system environment details, using
`not set` when either variable is absent.
- Report inherited `PAGER`, `GIT_PAGER`, `GH_PAGER`, and `LESS` values
when present.
- Preserve full values in local human output while reducing these fields
to `set` or `not set` in redacted JSON output.
- Add structured check, JSON-redaction, rendered-output, and snapshot
coverage.

## How to Test

1. From `codex-rs`, run Codex with explicit editor and pager variables:

   ```sh
env VISUAL='code --wait' EDITOR=vim PAGER='less -R' GIT_PAGER=delta
GH_PAGER=less LESS=-FRX \
     cargo run -p codex-cli --bin codex -- doctor --no-color
   ```

2. Confirm the `system` details show the full values for all six
variables.
3. Unset the pager variables and rerun the command. Confirm pager rows
are omitted while missing editor variables are shown as `not set`.
4. Run the same configured environment with `doctor --json`. Confirm
each configured editor or pager field is reported as `set` and none of
the raw commands or arguments appear in the JSON.

Targeted tests:

- `just test -p codex-cli` (279 tests passed)

codex-rs/cli/src/doctor.rs

@@ -682,7 +682,7 @@ fn structured_json_details(details: &[String]) -> (BTreeMap<String, JsonDetailVa
             notes.push(redacted);
             continue;
         }
-        let value = value.to_string();
+        let value = json_detail_value(key, value);
         match structured.get_mut(key) {
             Some(existing) => existing.push(value),
             None => {
@@ -693,6 +693,21 @@ fn structured_json_details(details: &[String]) -> (BTreeMap<String, JsonDetailVa
     (structured, notes)
 }
 
+fn json_detail_value(key: &str, value: &str) -> String {
+    if matches!(
+        key,
+        "VISUAL" | "EDITOR" | "PAGER" | "GIT_PAGER" | "GH_PAGER" | "LESS"
+    ) && !value.eq_ignore_ascii_case("not set")
+    {
+        // Editor and pager configuration can contain arbitrary arguments or
+        // inline environment assignments. Keep full values local to human output
+        // because the JSON report may be attached to feedback.
+        "set".to_string()
+    } else {
+        value.to_string()
+    }
+}
+
 fn run_sync_check(
     label: &'static str,
     progress: Arc<dyn DoctorProgress>,
@@ -3226,6 +3241,18 @@ mod tests {
             overall_status: CheckStatus::Warning,
             codex_version: "0.0.0".to_string(),
             checks: vec![
+                DoctorCheck::new(
+                    "system.environment",
+                    "system",
+                    CheckStatus::Ok,
+                    "OS language en-US",
+                )
+                .detail("VISUAL: code --wait")
+                .detail("EDITOR: env AWS_ACCESS_KEY_ID=AKIAEXAMPLE vim")
+                .detail("PAGER: env PRIVATE_PAGER_VALUE=pager-secret less")
+                .detail("GIT_PAGER: delta")
+                .detail("GH_PAGER: less")
+                .detail("LESS: -FRX"),
                 DoctorCheck::new(
                     "mcp.config",
                     "mcp",
@@ -3260,8 +3287,35 @@ mod tests {
         assert!(!redacted.contains("user:pass"));
         assert!(!redacted.contains("x=abc"));
         assert!(!redacted.contains("sk-live-secret"));
+        assert!(!redacted.contains("AKIAEXAMPLE"));
+        assert!(!redacted.contains("pager-secret"));
+        assert!(!redacted.contains("code --wait"));
         assert!(redacted.contains("https://example.com/mcp"));
         assert_eq!(json["checks"].is_object(), true);
+        assert_eq!(
+            json["checks"]["system.environment"]["details"]["VISUAL"],
+            "set"
+        );
+        assert_eq!(
+            json["checks"]["system.environment"]["details"]["EDITOR"],
+            "set"
+        );
+        assert_eq!(
+            json["checks"]["system.environment"]["details"]["PAGER"],
+            "set"
+        );
+        assert_eq!(
+            json["checks"]["system.environment"]["details"]["GIT_PAGER"],
+            "set"
+        );
+        assert_eq!(
+            json["checks"]["system.environment"]["details"]["GH_PAGER"],
+            "set"
+        );
+        assert_eq!(
+            json["checks"]["system.environment"]["details"]["LESS"],
+            "set"
+        );
         assert_eq!(json["checks"]["mcp.config"]["id"], "mcp.config");
         assert_eq!(
             json["checks"]["mcp.config"]["details"]["OPENAI_API_KEY"],

codex-rs/cli/src/doctor/output.rs

@@ -1133,7 +1133,13 @@ mod tests {
                 "OS language en-US",
             )
             .detail("os: macOS 15.0")
-            .detail("os language: en-US"),
+            .detail("os language: en-US")
+            .detail("VISUAL: code --wait")
+            .detail("EDITOR: vim")
+            .detail("PAGER: less -R")
+            .detail("GIT_PAGER: delta")
+            .detail("GH_PAGER: less")
+            .detail("LESS: -FRX"),
             DoctorCheck::new(
                 "runtime.provenance",
                 "runtime",
@@ -1246,6 +1252,12 @@ Environment
   ✓ system       en-US
       os                       macOS 15.0
       OS language              en-US
+      VISUAL                   code --wait
+      EDITOR                   vim
+      PAGER                    less -R
+      GIT_PAGER                delta
+      GH_PAGER                 less
+      LESS                     -FRX
   ✓ runtime      running local build on darwin-arm64
   ✓ install      consistent
       managed by               npm: no · bun: no · package root —

codex-rs/cli/src/doctor/output/detail.rs

@@ -62,6 +62,12 @@ fn system_details(parsed: &[ParsedDetail]) -> Vec<HumanDetail> {
     push_row_if_present(&mut out, parsed, "LC_ALL", "LC_ALL");
     push_row_if_present(&mut out, parsed, "LC_CTYPE", "LC_CTYPE");
     push_row_if_present(&mut out, parsed, "LANG", "LANG");
+    push_row_if_present(&mut out, parsed, "VISUAL", "VISUAL");
+    push_row_if_present(&mut out, parsed, "EDITOR", "EDITOR");
+    push_row_if_present(&mut out, parsed, "PAGER", "PAGER");
+    push_row_if_present(&mut out, parsed, "GIT_PAGER", "GIT_PAGER");
+    push_row_if_present(&mut out, parsed, "GH_PAGER", "GH_PAGER");
+    push_row_if_present(&mut out, parsed, "LESS", "LESS");
     push_remaining(
         &mut out,
         parsed,
@@ -73,6 +79,12 @@ fn system_details(parsed: &[ParsedDetail]) -> Vec<HumanDetail> {
             "LC_ALL",
             "LC_CTYPE",
             "LANG",
+            "VISUAL",
+            "EDITOR",
+            "PAGER",
+            "GIT_PAGER",
+            "GH_PAGER",
+            "LESS",
         ],
         &[],
     );

codex-rs/cli/src/doctor/snapshots/codex__doctor__output__tests__doctor_human_report_environment_rows.snap

@@ -13,6 +13,12 @@ Environment
   ✓ system       en-US
       os                       macOS 15.0
       OS language              en-US
+      VISUAL                   code --wait
+      EDITOR                   vim
+      PAGER                    less -R
+      GIT_PAGER                delta
+      GH_PAGER                 less
+      LESS                     -FRX
   ✓ runtime      running local build on darwin-arm64
   ✓ install      consistent
       managed by               npm: no · bun: no · package root —

codex-rs/cli/src/doctor/system.rs

@@ -4,6 +4,9 @@ use std::env;
 use super::DoctorCheck;
 use super::LOCALE_ENV_VARS;
 
+const EDITOR_ENV_VARS: &[&str] = &["VISUAL", "EDITOR"];
+const PAGER_ENV_VARS: &[&str] = &["PAGER", "GIT_PAGER", "GH_PAGER", "LESS"];
+
 #[derive(Clone, Debug, Default, Eq, PartialEq)]
 struct SystemCheckInputs {
     os: String,
@@ -11,6 +14,8 @@ struct SystemCheckInputs {
     os_version: String,
     os_language: Option<String>,
     locale_env: BTreeMap<String, String>,
+    editor_env: BTreeMap<String, String>,
+    pager_env: BTreeMap<String, String>,
 }
 
 impl SystemCheckInputs {
@@ -24,12 +29,30 @@ impl SystemCheckInputs {
                     .map(|value| ((*name).to_string(), value))
             })
             .collect();
+        let editor_env = EDITOR_ENV_VARS
+            .iter()
+            .map(|name| {
+                let value = env::var_os(name)
+                    .map(|value| value.to_string_lossy().into_owned())
+                    .unwrap_or_else(|| "not set".to_string());
+                ((*name).to_string(), value)
+            })
+            .collect();
+        let pager_env = PAGER_ENV_VARS
+            .iter()
+            .filter_map(|name| {
+                env::var_os(name)
+                    .map(|value| ((*name).to_string(), value.to_string_lossy().into_owned()))
+            })
+            .collect();
         Self {
             os: info.to_string(),
             os_type: info.os_type().to_string(),
             os_version: info.version().to_string(),
             os_language: sys_locale::get_locale(),
             locale_env,
+            editor_env,
+            pager_env,
         }
     }
 }
@@ -54,6 +77,16 @@ fn system_check_from_inputs(inputs: SystemCheckInputs) -> DoctorCheck {
             details.push(format!("{name}: {value}"));
         }
     }
+    for name in EDITOR_ENV_VARS {
+        if let Some(value) = inputs.editor_env.get(*name) {
+            details.push(format!("{name}: {value}"));
+        }
+    }
+    for name in PAGER_ENV_VARS {
+        if let Some(value) = inputs.pager_env.get(*name) {
+            details.push(format!("{name}: {value}"));
+        }
+    }
 
     let summary = inputs
         .os_language
@@ -76,20 +109,46 @@ mod tests {
     use super::*;
 
     #[test]
-    fn system_check_reports_os_language_and_locale_env() {
+    fn system_check_reports_os_language_locale_editor_and_pager_env() {
         let mut locale_env = BTreeMap::new();
         locale_env.insert("LANG".to_string(), "en_US.UTF-8".to_string());
+        let editor_env = BTreeMap::from([
+            ("EDITOR".to_string(), "vim".to_string()),
+            ("VISUAL".to_string(), "code --wait".to_string()),
+        ]);
+        let pager_env = BTreeMap::from([
+            ("GH_PAGER".to_string(), "less".to_string()),
+            ("GIT_PAGER".to_string(), "delta".to_string()),
+            ("LESS".to_string(), "-FRX".to_string()),
+            ("PAGER".to_string(), "less -R".to_string()),
+        ]);
         let check = system_check_from_inputs(SystemCheckInputs {
             os: "macOS 15.0".to_string(),
             os_type: "macos".to_string(),
             os_version: "15.0".to_string(),
             os_language: Some("en-US".to_string()),
             locale_env,
+            editor_env,
+            pager_env,
         });
 
         assert_eq!(check.summary, "OS language en-US");
-        assert!(check.details.contains(&"os language: en-US".to_string()));
-        assert!(check.details.contains(&"LANG: en_US.UTF-8".to_string()));
+        assert_eq!(
+            check.details,
+            vec![
+                "os: macOS 15.0",
+                "os type: macos",
+                "os version: 15.0",
+                "os language: en-US",
+                "LANG: en_US.UTF-8",
+                "VISUAL: code --wait",
+                "EDITOR: vim",
+                "PAGER: less -R",
+                "GIT_PAGER: delta",
+                "GH_PAGER: less",
+                "LESS: -FRX",
+            ]
+        );
     }
 
     #[test]
@@ -100,13 +159,24 @@ mod tests {
             os_version: "unknown".to_string(),
             os_language: None,
             locale_env: BTreeMap::new(),
+            editor_env: BTreeMap::from([
+                ("EDITOR".to_string(), "not set".to_string()),
+                ("VISUAL".to_string(), "not set".to_string()),
+            ]),
+            pager_env: BTreeMap::new(),
         });
 
         assert_eq!(check.summary, "OS language unavailable");
-        assert!(
-            check
-                .details
-                .contains(&"os language: unavailable".to_string())
+        assert_eq!(
+            check.details,
+            vec![
+                "os: Linux",
+                "os type: linux",
+                "os version: unknown",
+                "os language: unavailable",
+                "VISUAL: not set",
+                "EDITOR: not set",
+            ]
         );
     }
 }