diff --git a/.claude-plugin/plugin.json b/.claude-plugin/plugin.json
index 018f0384..b6be6fb4 100644
--- a/.claude-plugin/plugin.json
+++ b/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "commitlore",
   "displayName": "CommitLore",
-  "version": "1.2.3",
+  "version": "1.2.4",
   "description": "Recorded decisions from git history, delivered to the agent before it edits. Constraints, alternatives already ruled out, and warnings left by whoever was here last.",
   "author": {
     "name": "MongLong0214",
diff --git a/.codex-plugin/plugin.json b/.codex-plugin/plugin.json
index 15cc39b1..da184b0d 100644
--- a/.codex-plugin/plugin.json
+++ b/.codex-plugin/plugin.json
@@ -1,6 +1,6 @@
 {
   "name": "commitlore",
-  "version": "1.2.3",
+  "version": "1.2.4",
   "description": "Decision memory from Git history, with verified capture for coding sessions.",
   "author": {
     "name": "MongLong0214",
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8150c2b6..2bf2c752 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,39 @@ Release notes for 1.0.0, 1.0.1 and 1.0.2 are on the
 [GitHub releases page](https://github.com/MongLong0214/commitlore/releases); they
 were not written here.
 
+## 1.2.4
+
+`doctor` blamed the hook that worked, and prescribed reinstalling it.
+
+**`hook-runtime` attributed a preserved hook's failure to commitlore's hook
+(#876).** The installed stub runs the hook it preserved at install time first and
+exits with that hook's code, verbatim, before commitlore is resolved. Probed as
+one process, a preserved hook that called `node` by name died with 127 under
+git's PATH and the row read "the hook cannot find a node interpreter", with
+`commitlore hooks install` as the fix. That command rewrites only commitlore's
+own file; it reported the file unchanged, and the next `doctor` failed
+identically. The reporter spent several minutes repairing the wrong component,
+because the diagnostic named it.
+
+**The preserved hook now runs on its own first**, under the same PATH-less
+environment and through `sh` the way the stub invokes it. If it exits non-zero,
+the row says commitlore's hook is not what failed, names the preserved hook by
+path, classifies its first stderr line the same way the stub's was (node
+missing, node threw, unclear), and prescribes a fix aimed at that file. Only once
+it has passed does the stub run, so every remaining failure is commitlore's own
+resolution and `hooks install` is once again a remedy that can move it.
+
+**`commit-msg-hook` inherits the fix along with the outcome.** It was the row the
+reporter read: it already carried the runtime row's outcome when blocked on it,
+and kept saying `hooks install` under an outcome that had just explained why
+that could not help.
+
+Not changed: a broken preserved hook still blocks every commit. That is the
+chaining contract — a hook that was rejecting commits before commitlore arrived
+must keep rejecting them — and whether a hook that is broken rather than
+rejecting deserves different treatment is a separate decision from a diagnostic
+one.
+
 ## 1.2.3
 
 The capture prompt was the session, so on a long session there was no prompt.
diff --git a/README.ja.md b/README.ja.md
index 1ccf4a88..2fb227b1 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -47,18 +47,18 @@
 </p>
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 ```
 
 <details>
 <summary>先にインストーラーを読みたいですか？</summary>
 
 ```bash
-curl -fsSLO https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh
-sh install.sh v1.2.3
+curl -fsSLO https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh
+sh install.sh v1.2.4
 
 # あるいはスクリプトを使わずに。スクリプトが作るチェックアウトは自分でも作れます。
-git clone --depth 1 --branch v1.2.3 https://github.com/MongLong0214/commitlore
+git clone --depth 1 --branch v1.2.4 https://github.com/MongLong0214/commitlore
 node commitlore/dist/commitlore.mjs --version
 ```
 
@@ -107,13 +107,13 @@ CommitLore はその判断をコードのそばに残します。
 macOS と Linux:
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 ```
 
 Windows:
 
 ```powershell
-& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.ps1))) v1.2.3
+& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.ps1))) v1.2.4
 ```
 
 Node.js 22.23.2+ と Git が必要です。スクリプトは何かを書き込む前に両方を確認します。
diff --git a/README.ko.md b/README.ko.md
index c5bb0b9f..a5883f2c 100644
--- a/README.ko.md
+++ b/README.ko.md
@@ -47,18 +47,18 @@
 </p>
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 ```
 
 <details>
 <summary>먼저 설치기를 읽어 보고 싶나요?</summary>
 
 ```bash
-curl -fsSLO https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh
-sh install.sh v1.2.3
+curl -fsSLO https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh
+sh install.sh v1.2.4
 
 # 또는 스크립트를 건너뜁니다. 스크립트가 만드는 체크아웃은 직접 만들 수 있습니다.
-git clone --depth 1 --branch v1.2.3 https://github.com/MongLong0214/commitlore
+git clone --depth 1 --branch v1.2.4 https://github.com/MongLong0214/commitlore
 node commitlore/dist/commitlore.mjs --version
 ```
 
@@ -107,13 +107,13 @@ CommitLore는 그 판단을 코드 곁에 보관합니다.
 macOS와 Linux:
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 ```
 
 Windows:
 
 ```powershell
-& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.ps1))) v1.2.3
+& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.ps1))) v1.2.4
 ```
 
 Node.js 22.23.2+와 Git이 필요합니다. 스크립트는 무엇이든 쓰기 전에 둘을 확인합니다.
diff --git a/README.md b/README.md
index 9c0d0634..365acbd0 100644
--- a/README.md
+++ b/README.md
@@ -48,18 +48,18 @@
 </p>
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 ```
 
 <details>
 <summary>Prefer to read the installer first?</summary>
 
 ```bash
-curl -fsSLO https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh
-sh install.sh v1.2.3
+curl -fsSLO https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh
+sh install.sh v1.2.4
 
 # Or skip the script: the checkout it makes is one you can make yourself.
-git clone --depth 1 --branch v1.2.3 https://github.com/MongLong0214/commitlore
+git clone --depth 1 --branch v1.2.4 https://github.com/MongLong0214/commitlore
 node commitlore/dist/commitlore.mjs --version
 ```
 
@@ -109,13 +109,13 @@ preserve, not for narrating every change.
 macOS and Linux:
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 ```
 
 Windows:
 
 ```powershell
-& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.ps1))) v1.2.3
+& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.ps1))) v1.2.4
 ```
 
 Requires Node.js 22.23.2+ and Git. The script checks both before it writes anything.
diff --git a/README.zh-CN.md b/README.zh-CN.md
index 337ab275..8790036f 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -47,18 +47,18 @@
 </p>
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 ```
 
 <details>
 <summary>想先阅读安装器吗？</summary>
 
 ```bash
-curl -fsSLO https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh
-sh install.sh v1.2.3
+curl -fsSLO https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh
+sh install.sh v1.2.4
 
 # 或者跳过脚本：它创建的检出，你自己也能创建。
-git clone --depth 1 --branch v1.2.3 https://github.com/MongLong0214/commitlore
+git clone --depth 1 --branch v1.2.4 https://github.com/MongLong0214/commitlore
 node commitlore/dist/commitlore.mjs --version
 ```
 
@@ -105,13 +105,13 @@ CommitLore 把那份判断留在代码旁边。
 macOS 和 Linux：
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 ```
 
 Windows：
 
 ```powershell
-& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.ps1))) v1.2.3
+& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.ps1))) v1.2.4
 ```
 
 需要 Node.js 22.23.2+ 和 Git。脚本会在写入任何内容前检查两者。
diff --git a/install.ps1 b/install.ps1
index 055f8561..24558bcb 100644
--- a/install.ps1
+++ b/install.ps1
@@ -1,8 +1,8 @@
 <#
     Installs commitlore from source on Windows, for any agent that is not Claude Code.
 
-      irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.ps1 | iex
-      & ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.ps1))) v1.2.3
+      irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.ps1 | iex
+      & ([scriptblock]::Create((irm https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.ps1))) v1.2.4
 
     Claude Code users do not need this script. The repository is itself a plugin
     marketplace (ADR-0011), so two /plugin commands register the MCP server, the
diff --git a/install.sh b/install.sh
index f77ed7cb..c69df874 100755
--- a/install.sh
+++ b/install.sh
@@ -1,8 +1,8 @@
 #!/bin/sh
 # Installs commitlore from source, for any agent that is not Claude Code.
 #
-#   curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh
-#   curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3
+#   curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh
+#   curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4
 #
 # **Claude Code users do not need this script.** The repository is itself a
 # plugin marketplace (ADR-0011), so two `/plugin` commands register the MCP
diff --git a/package-lock.json b/package-lock.json
index 282256ab..5730f28a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "commitlore",
-  "version": "1.2.3",
+  "version": "1.2.4",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "commitlore",
-      "version": "1.2.3",
+      "version": "1.2.4",
       "license": "MIT",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.30.0",
diff --git a/package.json b/package.json
index e3d0c2a1..b1b7b646 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "commitlore",
-  "version": "1.2.3",
+  "version": "1.2.4",
   "description": "Git-native, lifecycle-aware decision memory for coding agents",
   "license": "MIT",
   "private": true,
diff --git a/server.json b/server.json
index 503946f5..6e4f9cb6 100644
--- a/server.json
+++ b/server.json
@@ -8,7 +8,7 @@
     "source": "github"
   },
   "websiteUrl": "https://github.com/MongLong0214/commitlore#readme",
-  "version": "1.2.3",
+  "version": "1.2.4",
   "_meta": {
     "io.modelcontextprotocol.registry/publisher-provided": {
       "registryFit": "Distribution is a tagged git checkout plus a Claude Code plugin marketplace (ADR-0011 registry-free git distribution, ADR-0026 no compiled executables and no uploaded release asset), so no official package type applies and this record relies on websiteUrl plus publisher metadata.",
@@ -18,8 +18,8 @@
           "/plugin marketplace add MongLong0214/commitlore",
           "/plugin install commitlore@commitlore"
         ],
-        "installer": "curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.3/install.sh | sh -s v1.2.3",
-        "release": "https://github.com/MongLong0214/commitlore/releases/tag/v1.2.3"
+        "installer": "curl -fsSL https://raw.githubusercontent.com/MongLong0214/commitlore/v1.2.4/install.sh | sh -s v1.2.4",
+        "release": "https://github.com/MongLong0214/commitlore/releases/tag/v1.2.4"
       },
       "runtime": {
         "transport": "stdio",
diff --git a/src/commands/doctor/checks/capture-commit-msg-hook.ts b/src/commands/doctor/checks/capture-commit-msg-hook.ts
index dc7471f9..73f3cbf1 100644
--- a/src/commands/doctor/checks/capture-commit-msg-hook.ts
+++ b/src/commands/doctor/checks/capture-commit-msg-hook.ts
@@ -115,6 +115,11 @@ export const checkHook = (ctx: DoctorContext, runtime?: DoctorCheck): DoctorChec
   ];
   if (runtime !== undefined && runtime.status !== 'ok') {
     const inherited = `installed at ${path}; ${targetDetail}; outcome: ${runtime.detail}`;
+    // This row is blocked on the runtime's finding, so the fix that moves that
+    // finding is the only fix that moves this one. Prescribing `hooks install`
+    // here regardless is how a preserved hook's failure came to carry a remedy
+    // that reinstalls the hook which worked (#876).
+    const inheritedFix = runtime.fix ?? install;
     // A skipped runtime would make this row a skip too, and a skip has to name
     // a reason. Inheriting the runtime's is the only answer that stays true —
     // this row did not look for the same reason that one did not. The branch is
@@ -130,7 +135,7 @@ export const checkHook = (ctx: DoctorContext, runtime?: DoctorCheck): DoctorChec
           title,
           'skipped',
           inherited,
-          install,
+          inheritedFix,
           false,
           false,
           {
@@ -148,7 +153,7 @@ export const checkHook = (ctx: DoctorContext, runtime?: DoctorCheck): DoctorChec
         title,
         runtime.status,
         inherited,
-        install,
+        inheritedFix,
         false,
         undefined,
         { evidence: { ...hookEvidence, runtime_status: runtime.status } },
diff --git a/src/commands/doctor/checks/capture-hook-runtime.ts b/src/commands/doctor/checks/capture-hook-runtime.ts
index 9d2b018b..b7f554a2 100644
--- a/src/commands/doctor/checks/capture-hook-runtime.ts
+++ b/src/commands/doctor/checks/capture-hook-runtime.ts
@@ -5,12 +5,39 @@
  * receive its completed row through the registry rather than importing it.
  */
 
-import { existsSync, rmSync, writeFileSync } from 'node:fs';
+import { accessSync, constants as fsConstants, existsSync, rmSync, writeFileSync } from 'node:fs';
 import { tmpdir as tmpdirPath } from 'node:os';
-import { join, resolve } from 'node:path';
+import { dirname, join, resolve } from 'node:path';
 
+import { CHAINED_HOOK_NAME } from '../../../hooks/commit-msg.js';
 import { check, gitOptions, PROBE_MESSAGE, streamEvidence, type Category, type DoctorCheck, type DoctorContext } from '../model.js';
 
+/**
+ * The stub runs `"$chained" "$@"` only when `[ -x "$chained" ]` holds, so a
+ * preserved hook without its execute bit is inert to git and to the stub alike.
+ * The same test here, so this check does not probe a file the hook will skip.
+ */
+const isExecutable = (path: string): boolean => {
+  try {
+    accessSync(path, fsConstants.X_OK);
+    return true;
+  } catch {
+    return false;
+  }
+};
+
+/**
+ * How the stub's failure reads on its first stderr line: node was never found,
+ * node ran and threw, or neither. Shared between the two hooks this check runs,
+ * because the preserved hook fails in the same three shapes and the
+ * classification is about the line, not about who wrote it.
+ */
+const classifyFailure = (status: number | null, said: string): 'node-missing' | 'node-threw' | 'unclear' => {
+  if (status === 127 || /\bnode\b.*not found|ENOENT|command not found.*\bnode\b/i.test(said)) return 'node-missing';
+  if (/^\s*at\s|\.js:\d+/.test(said)) return 'node-threw';
+  return 'unclear';
+};
+
 /**
  * Whether the installed hook actually runs, in the environment git gives it.
  *
@@ -29,6 +56,12 @@ import { check, gitOptions, PROBE_MESSAGE, streamEvidence, type Category, type D
  * The probe message is valid, so a healthy hook exits 0. A hook that cannot find
  * a runtime exits non-zero having parsed nothing, which is indistinguishable
  * from "your message was fine" to everyone except this check.
+ *
+ * Two hooks run here, not one. The stub hands the message to the hook it
+ * preserved at install time before it resolves commitlore, and exits with that
+ * hook's code if it fails -- so the preserved hook is probed on its own first,
+ * and its failure is reported as its own, with a fix aimed at it. `hooks
+ * install` cannot move a finding about a file it does not write (#876).
  */
 export const checkHookRuntime = (ctx: DoctorContext): DoctorCheck => {
   const { opts, git, spawn, env } = ctx;
@@ -77,15 +110,71 @@ export const checkHookRuntime = (ctx: DoctorContext): DoctorCheck => {
   }
 
   const probe = join(tmpdirPath(), `commitlore-doctor-${String(process.pid)}.txt`);
+  // No node, and no PATH entry that could supply one. `git` must stay
+  // reachable: the hook reads its own config through it.
+  const hookEnv = { PATH: '/usr/bin:/bin', HOME: env['HOME'] ?? '' };
   try {
+    // The stub runs the hook it preserved at install time first, and that
+    // hook's non-zero exit is the stub's exit, verbatim, before commitlore is
+    // reached. Probed through the stub alone, the two are one process with one
+    // stderr, and the row attributed a preserved hook's `node: command not
+    // found` to the installed hook and prescribed `hooks install` -- which
+    // reports the file unchanged, because the file it writes was never the one
+    // failing (#876). So the preserved hook runs on its own first, the way the
+    // stub runs it: through sh, so a script without a shebang behaves the same
+    // here as it does there.
+    const chained = join(dirname(hook), CHAINED_HOOK_NAME);
+    if (isExecutable(chained)) {
+      writeFileSync(probe, PROBE_MESSAGE);
+      const preserved = spawn('/bin/sh', ['-c', '"$0" "$1"', chained, probe], {
+        shell: false,
+        encoding: 'utf8',
+        cwd,
+        env: hookEnv,
+      });
+      const exit = preserved.error === undefined ? preserved.status : null;
+      if (preserved.error !== undefined || exit !== 0) {
+        const spoke = `${preserved.stderr ?? ''}`.trim();
+        const said = preserved.error?.message ?? (spoke.split('\n')[0] ?? '');
+        const shape = preserved.error === undefined ? classifyFailure(exit, said) : 'unclear';
+        const because =
+          shape === 'node-missing'
+            ? `it calls node by name and git's PATH has none: ${said}`
+            : shape === 'node-threw'
+              ? `its node process ran but threw (exit ${String(exit)}): ${said}`
+              : `it exited ${String(exit ?? 'unavailable')} under the restricted PATH: ${said || 'no output'}`;
+        return check(
+          id,
+          category,
+          title,
+          'fail',
+          `commitlore's hook is not what failed. It runs the hook it preserved first, and that hook -- ${chained} -- stops the commit before commitlore is reached: ${because}. That file was this repository's commit-msg hook before commitlore was installed; \`hooks install\` rewrites only commitlore's own and leaves it as it is`,
+          shape === 'node-missing'
+            ? `edit ${chained} to call node by absolute path (or remove it if it is no longer wanted)`
+            : `fix or remove ${chained}`,
+          false,
+          undefined,
+          {
+            evidence: {
+              hook_path: hook,
+              chained_hook_path: chained,
+              exit_code: String(exit ?? 'unavailable'),
+              ...(preserved.error === undefined ? {} : { error: preserved.error.message }),
+              ...streamEvidence('stderr', preserved.stderr ?? ''),
+            },
+          },
+        );
+      }
+    }
+
+    // A commit-msg hook may rewrite the message it is given; the probe is
+    // written again so the stub reads the same bytes the preserved hook did.
     writeFileSync(probe, PROBE_MESSAGE);
     const run = spawn('/bin/sh', [hook, probe], {
       shell: false,
       encoding: 'utf8',
       cwd,
-      // No node, and no PATH entry that could supply one. `git` must stay
-      // reachable: the hook reads its own config through it.
-      env: { PATH: '/usr/bin:/bin', HOME: env['HOME'] ?? '' },
+      env: hookEnv,
     });
 
     if (run.error !== undefined) {
@@ -111,10 +200,11 @@ export const checkHookRuntime = (ctx: DoctorContext): DoctorCheck => {
     if (run.status !== 0) {
       const spoke = `${run.stderr ?? ''}`.trim();
       const said = spoke.split('\n')[0] ?? '';
-      const nodeMissing =
-        run.status === 127 ||
-        /\bnode\b.*not found|ENOENT|command not found.*\bnode\b/i.test(said);
-      const nodeThrew = /^\s*at\s|\.js:\d+/.test(said);
+      // The preserved hook, if any, has already exited 0 on its own above, so
+      // whatever follows is commitlore's resolution failing, not a hand-off.
+      const shape = classifyFailure(run.status, said);
+      const nodeMissing = shape === 'node-missing';
+      const nodeThrew = shape === 'node-threw';
       // The stub says this when the recorded pair resolved and the containment
       // check refused it: present, executable, and under a tree this install
       // did not record. An upgrade produces it, because `commitlore.bin` follows
diff --git a/test/doctor.test.ts b/test/doctor.test.ts
index ad80e0e2..c66f8488 100644
--- a/test/doctor.test.ts
+++ b/test/doctor.test.ts
@@ -42,7 +42,7 @@ import { POLICY_FILE_NAME } from '../src/core/capture-policy.js';
 import { REQUIRE_SIGNED_DIRECTIVE_KEY } from '../src/core/trusted-authors.js';
 // The real stub T-202 installs — doctor must recognize that exact file, so the
 // fixture is the installer's own output rather than a lookalike.
-import { HOOK_MARKER, commitMsgStub } from '../src/hooks/commit-msg.js';
+import { CHAINED_HOOK_NAME, HOOK_MARKER, commitMsgStub } from '../src/hooks/commit-msg.js';
 import {
   CLAUDE_HOOK_MARKER,
   claudeSettingsPath,
@@ -655,6 +655,96 @@ describe('doctor: hook runtime', () => {
     expect(runtime?.detail).toMatch(/unclear|cannot determine/i);
     expect(runtime?.detail).not.toContain('carries no node');
   });
+
+  /**
+   * #876. The stub runs the hook it preserved at install time first and exits
+   * with that hook's code, so a preserved hook that calls `node` by name dies
+   * with 127 before commitlore is reached. Probed as one process, the row read
+   * that as commitlore's hook failing and prescribed `hooks install`, which
+   * reported the file unchanged and left the failure exactly where it was. The
+   * row has to name the file that produced the exit and offer a fix that can
+   * move it.
+   */
+  const chainedPath = (repo: string): string => join(dirname(hookPath(repo)), CHAINED_HOOK_NAME);
+
+  it('names the preserved hook, not the installed one, when the preserved hook cannot find node', () => {
+    const repo = initRepo('doctor-runtime-chained-no-node');
+    installedHook(repo);
+    // The shape of the reporter's hook: a repository's own commit-msg calling
+    // node by name, which is fine on an interactive PATH and 127 on git's.
+    writeScript(chainedPath(repo), '#!/bin/sh\nexec node /nonexistent/lint-commit.js "$@"\n');
+    chmodSync(chainedPath(repo), 0o755);
+
+    const report = runDoctor({ cwd: repo });
+    const runtime = report.checks.find((entry) => entry.id === 'hook-runtime');
+    expect(runtime?.status).toBe('fail');
+    expect(runtime?.detail).toContain(chainedPath(repo));
+    expect(runtime?.detail).toMatch(/commitlore's hook is not what failed/);
+    expect(runtime?.detail).toContain('node');
+    expect(runtime?.fix).toContain(chainedPath(repo));
+    expect(runtime?.fix).not.toContain('hooks install');
+    // The row the reporter read was `commit-msg-hook`, which inherits the
+    // runtime's outcome. It has to inherit the remedy too, or it keeps saying
+    // `hooks install` under an outcome that just explained why that cannot help.
+    const installation = report.checks.find((entry) => entry.id === 'commit-msg-hook');
+    expect(installation?.status).toBe('fail');
+    expect(installation?.blockedBy).toBe('hook-runtime');
+    expect(installation?.fix).toContain(chainedPath(repo));
+    expect(installation?.fix).not.toContain('hooks install');
+    // Evidence paths are normalised (a home prefix becomes `~`), so the name
+    // is what is pinned, not the absolute string.
+    expect(runtime?.evidence['chained_hook_path']?.endsWith(`/${CHAINED_HOOK_NAME}`)).toBe(true);
+    expect(runtime?.evidence['exit_code']).toBe('127');
+  });
+
+  it('names the preserved hook when it exits non-zero for a reason unrelated to node', () => {
+    const repo = initRepo('doctor-runtime-chained-broken');
+    installedHook(repo);
+    writeScript(chainedPath(repo), '#!/bin/sh\necho "lint config missing" >&2\nexit 3\n');
+    chmodSync(chainedPath(repo), 0o755);
+
+    const runtime = runtimeCheck(repo);
+    expect(runtime?.status).toBe('fail');
+    expect(runtime?.detail).toContain(chainedPath(repo));
+    expect(runtime?.detail).toContain('lint config missing');
+    expect(runtime?.detail).not.toMatch(/the hook cannot find a node interpreter/);
+    expect(runtime?.fix).toContain(chainedPath(repo));
+    expect(runtime?.fix).not.toContain('hooks install');
+    expect(runtime?.evidence['exit_code']).toBe('3');
+  });
+
+  it('still runs the installed hook, and blames it, once the preserved hook has passed', () => {
+    const repo = initRepo('doctor-runtime-chained-ok-then-node-gone');
+    installedHook(repo);
+    writeScript(chainedPath(repo), '#!/bin/sh\nexit 0\n');
+    chmodSync(chainedPath(repo), 0o755);
+    git(repo, ['config', '--local', 'commitlore.node', '/nonexistent/node']);
+
+    const runtime = runtimeCheck(repo);
+    expect(runtime?.status).toBe('fail');
+    expect(runtime?.detail).not.toMatch(/commitlore's hook is not what failed/);
+    expect(runtime?.fix).toContain('hooks install');
+    expect(runtime?.evidence['chained_hook_path']).toBeUndefined();
+  });
+
+  it('reports ok when the preserved hook passes and so does the installed one', () => {
+    const repo = initRepo('doctor-runtime-chained-ok');
+    installedHook(repo);
+    writeScript(chainedPath(repo), '#!/bin/sh\nexit 0\n');
+    chmodSync(chainedPath(repo), 0o755);
+
+    expect(runtimeCheck(repo)?.status).toBe('ok');
+  });
+
+  it('ignores a preserved hook without its execute bit, as the stub does', () => {
+    // `[ -x "$chained" ]` in the stub: git would not have run this file either.
+    const repo = initRepo('doctor-runtime-chained-inert');
+    installedHook(repo);
+    writeScript(chainedPath(repo), '#!/bin/sh\nexit 1\n');
+    chmodSync(chainedPath(repo), 0o644);
+
+    expect(runtimeCheck(repo)?.status).toBe('ok');
+  });
 });
 
 describe('doctor: PreToolUse hook runtime', () => {