diff --git a/test/gstack-capy-install.test.ts b/test/gstack-capy-install.test.ts
index e801a18f4..3baf26a36 100644
--- a/test/gstack-capy-install.test.ts
+++ b/test/gstack-capy-install.test.ts
@@ -477,6 +477,31 @@ describe('gstack-capy-install: launch PATH, Bun reuse, CI pins, setup skip, verd
       fs.chmodSync(dir, 0o755);
     }
   });
+
+  // protects: when the launch file's temp file IS created and the final mv fails, write_launch_file
+  // removes its own temp file and nothing else (a sibling temp file from a concurrent run survives),
+  // the run says so, prints no GSTACK_LAUNCH_FILE line and keeps the earlier launch file, exit code
+  // and trailer. fails_when: the `|| { rm -f "$tmp"; return 1; }` cleanup goes (the temp file stays),
+  // or a glob cleanup returns (the sibling disappears). why_existing_misses: the unwritable-directory
+  // case above fails at mktemp, before any temp file exists. seam: an mv shim first on PATH that
+  // refuses only the launch-file target.
+  test('a launch-file move that fails after the temp file exists removes only that temp file', () => {
+    const f = fixture();
+    const first = run(f, ['--for', 'autoplan']);
+    expect(first.status, first.stdout + first.stderr).toBe(0);
+    const launchFile = first.stdout.match(/^GSTACK_LAUNCH_FILE: (.+)$/m)?.[1] ?? '';
+    const before = fs.readFileSync(launchFile, 'utf8');
+    const sibling = `${launchFile}.tmp.OTHER1`;
+    fs.writeFileSync(sibling, '');
+    script(path.join(f.stub, 'mv'), [`for a in "$@"; do [ "$a" = "${launchFile}" ] && exit 1; done`, 'exec /bin/mv "$@"']);
+    const c = run(f, ['--check', '--for', 'autoplan']);
+    expect(c.status, c.stdout + c.stderr).toBe(0);
+    expect(c.stdout).toContain(`gstack-capy-install: could not write the launch file ${launchFile}`);
+    expect(c.stdout).not.toMatch(/^GSTACK_LAUNCH_FILE:/m);
+    expect(lastLine(c.stdout)).toBe('gstack: ok 1.2.3 for=autoplan');
+    expect(fs.readdirSync(path.dirname(launchFile)).filter(n => n.includes('.tmp.'))).toEqual([path.basename(sibling)]);
+    expect(fs.readFileSync(launchFile, 'utf8')).toBe(before);
+  });
 });
 
 // Plan A1/A3/A5/A6/A-f: install and --check resolve through one contract,
diff --git a/test/launch-env-echo-ratchet.test.ts b/test/launch-env-echo-ratchet.test.ts
index f6bc6dcf8..c74f6b159 100644
--- a/test/launch-env-echo-ratchet.test.ts
+++ b/test/launch-env-echo-ratchet.test.ts
@@ -111,13 +111,13 @@ function markdownTargets(): string[] {
     /^capy\/skill\/gstack\/[^/]+\.md$/.test(rel));
 }
 
-/** Every shell helper under bin/, the setup script and the install scripts callers run first. */
+/** Every shell helper under bin/, the setup script and the scripts/*.sh build and doctor scripts. */
 function shellTargets(): string[] {
   const candidates = [...fs.readdirSync(path.join(ROOT, 'bin')).map(name => path.join('bin', name)), 'setup',
     ...fs.readdirSync(path.join(ROOT, 'scripts')).filter(name => name.endsWith('.sh')).map(name => path.join('scripts', name))];
   return candidates.filter(rel => {
     const full = path.join(ROOT, rel);
-    return fs.existsSync(full) && fs.statSync(full).isFile() && isShell(rel, fs.readFileSync(full, 'utf8'));
+    return fs.statSync(full).isFile() && isShell(rel, fs.readFileSync(full, 'utf8'));
   });
 }
 
@@ -164,7 +164,7 @@ describe('launch-env echo ratchet', () => {
     for (const want of ['ship/SKILL.md', 'ship/sections/documentation.md', 'review/SKILL.md', 'qa/SKILL.md',
       'document-release/SKILL.md', 'autoplan/DRIVER.md', 'capy/skill/gstack/SKILL.md']) expect(md).toContain(want);
     const sh = shellTargets();
-    for (const want of ['bin/gstack-capy-install', 'bin/gstack-capy-session', 'bin/gstack-skill-start']) expect(sh).toContain(want);
+    for (const want of ['bin/gstack-capy-install', 'bin/gstack-capy-session', 'bin/gstack-skill-start', 'setup', 'scripts/build.sh', 'scripts/sandbox-doctor.sh']) expect(sh).toContain(want);
   });
 
   test('no skill fence prints the environment', () => {
@@ -172,7 +172,7 @@ describe('launch-env echo ratchet', () => {
     expect(violations.map(v => `${v.file}:${v.line} [${v.rule}] ${v.text}`)).toEqual([]);
   });
 
-  test('no shell helper under bin/ prints the environment', () => {
+  test('no shell helper under bin/, setup or install script prints the environment', () => {
     const violations = shellTargets().flatMap(file => scanText(file, fs.readFileSync(path.join(ROOT, file), 'utf8'), 'whole'));
     expect(violations.map(v => `${v.file}:${v.line} [${v.rule}] ${v.text}`)).toEqual([]);
   });