@@ -179,8 +179,8 @@ export function objectstackDependencySpec(placement: ScaffoldPlacement): string
  * here, and never this range for `standalone`.
  *
  * `test/create-in-repo-scaffold-typechecks.test.ts` pins it equal to the range
- * the repository root and every sibling under `packages/plugins/` declare, so a
- * workspace TypeScript bump reddens there until this moves with it.
+ * this package declares (the root and every sibling package declare the same
+ * one), so a workspace TypeScript bump reddens there until this moves with it.
  */
 export const IN_REPO_TYPESCRIPT_RANGE = '^6.0.3';
 
 
@@ -34,9 +34,10 @@
  *
  * The TypeScript VERSION a contributor installs cannot be spawned here without
  * an install, so the TS5103 half is pinned on the declaration instead: the
- * in-repo range is the workspace's range, and its floor is a major that
- * accepts the base's `ignoreDeprecations`. The standalone range is pinned
- * unchanged beside it.
+ * in-repo range is the range this package declares for the very `tsc` the
+ * cases spawn (the workspace's TypeScript, which the root and every sibling
+ * declare too), and its floor is a major that accepts the base's
+ * `ignoreDeprecations`. The standalone range is pinned unchanged beside it.
  *
  * ## The control
  *
@@ -56,9 +57,8 @@ import { SCAFFOLD_TYPESCRIPT_RANGE } from '../src/commands/init.js';
 import { childEnv } from './helpers/serve-process.js';
 
 const HERE = path.dirname(fileURLToPath(import.meta.url));
-const REPO_ROOT = path.resolve(HERE, '../../..');
+const PKG = path.resolve(HERE, '..');
 const BASE_TSCONFIG = path.resolve(HERE, '../../..', 'tsconfig.base.json');
-const PLUGINS_DIR = path.resolve(HERE, '../../..', 'packages/plugins');
 
 const require = createRequire(import.meta.url);
 const TSC = require.resolve('typescript/bin/tsc');
@@ -143,20 +143,10 @@ describe('os create plugin --in-repo: the scaffold passes its own scripts', () =
 });
 
 describe('os create plugin: the TypeScript each placement declares', () => {
-  it('in-repo declares the workspace\'s TypeScript, the range the root and every sibling plugin declare', () => {
-    const root = JSON.parse(fs.readFileSync(path.join(REPO_ROOT, 'package.json'), 'utf8')) as Manifest;
-    expect(manifestFor('in-repo').devDependencies.typescript).toBe(root.devDependencies.typescript);
-    expect(IN_REPO_TYPESCRIPT_RANGE).toBe(root.devDependencies.typescript);
-
-    const siblings = fs
-      .readdirSync(PLUGINS_DIR)
-      .map((name) => path.join(PLUGINS_DIR, name, 'package.json'))
-      .filter((file) => fs.existsSync(file))
-      .map((file) => JSON.parse(fs.readFileSync(file, 'utf8')) as Partial<Manifest>)
-      .map((pkg) => pkg.devDependencies?.typescript)
-      .filter((range): range is string => typeof range === 'string');
-    expect(siblings.length, 'no sibling under packages/plugins declares typescript').toBeGreaterThan(0);
-    expect([...new Set(siblings)]).toEqual([IN_REPO_TYPESCRIPT_RANGE]);
+  it('in-repo declares the workspace\'s TypeScript, the range of the tsc the cases above spawn', () => {
+    const own = JSON.parse(fs.readFileSync(path.join(PKG, 'package.json'), 'utf8')) as Manifest;
+    expect(manifestFor('in-repo').devDependencies.typescript).toBe(own.devDependencies.typescript);
+    expect(IN_REPO_TYPESCRIPT_RANGE).toBe(own.devDependencies.typescript);
   });
 
   it('in-repo\'s TypeScript floor accepts the base\'s ignoreDeprecations (TS5103)', () => {
 
@@ -1458,8 +1458,11 @@ export const TOP_LEVEL_DIRECTORIES_AWAITING_IMPORT = Object.freeze({});
  * Repo-root FILES declared as `$TURBO_ROOT$` inputs -- the fourth shape, pinned, not collected.
  * `vitest.preset.mts` is the shared vitest preset the package configs re-export by
  * relative import; it is the `test` task's input so an edit to it reruns their suites.
+ * `tsconfig.base.json` is `@objectstack/cli#test`'s: the in-repo scaffold test copies
+ * it into its sandbox. It is a turbo `globalDependencies` entry too, which this gate
+ * does not read, so the task declares it as well.
  */
-export const TURBO_ROOT_FILE_INPUTS = Object.freeze(['sdui.manifest.json', 'vitest.preset.mts']);
+export const TURBO_ROOT_FILE_INPUTS = Object.freeze(['sdui.manifest.json', 'tsconfig.base.json', 'vitest.preset.mts']);
 
 /** `.` is the only regex metacharacter these names carry today; escape the class anyway. */
 const TOP_LEVEL_ALTERNATION = RECOGNISED_TOP_LEVEL_DIRECTORIES
 
@@ -728,6 +728,13 @@ export const CROSS_PACKAGE_TEST_INPUTS = {
       // their trees: the pin reads nothing else from either package.
       'packages/spec/src/data/hook.zod.ts',
       'packages/runtime/src/sandbox/body-runner.ts',
+      // The repo-root base every package extends. test/create-in-repo-scaffold-typechecks.test.ts
+      // copies it into a sandbox laid out like this repo and type-checks an
+      // `os create plugin --in-repo` scaffold under it, so a strictness or
+      // `ignoreDeprecations` change in the base is exactly what must re-run
+      // this suite. It is a turbo `globalDependencies` entry as well, which
+      // this roster does not read.
+      'tsconfig.base.json',
     ],
     heldBy: {
       // The parity pin joins each barrel path from `SCAFFOLD_WIRED_BARRELS`, a
 
@@ -255,6 +255,7 @@
         "!**/node_modules/**",
         "$TURBO_ROOT$/scripts/nightly-tiers.mjs",
         "$TURBO_ROOT$/scripts/nightly-tiers.d.mts",
+        "$TURBO_ROOT$/tsconfig.base.json",
         "$TURBO_ROOT$/packages/verify/src/**",
         "$TURBO_ROOT$/packages/plugins/plugin-security/src/**",
         "$TURBO_ROOT$/packages/services/service-cluster/src/**",