diff --git a/.changeset/30467-ledger-adoption-staging-dir.md b/.changeset/30467-ledger-adoption-staging-dir.md
new file mode 100644
index 00000000000..c0ab0f30047
--- /dev/null
+++ b/.changeset/30467-ledger-adoption-staging-dir.md
@@ -0,0 +1,8 @@
+---
+'@objectstack/cloud-connection': patch
+---
+
+Clause-②: no
+Metadata-protocol: none
+
+The one-time copy of the working-directory install ledger into its `OS_HOME` location (#30217) now creates its staging directory with an exclusive `mkdirSync` of a randomly named sibling instead of `mkdtempSync`. Behaviour is unchanged: the copy still lands in a unique sibling of the ledger directory, is renamed into place, and is removed if the copy fails. This repairs the red `main` build (#30467), where the repository's in-tree scratch scan could not read the `mkdtempSync` base.
diff --git a/packages/cloud-connection/src/local-manifest-source.ts b/packages/cloud-connection/src/local-manifest-source.ts
index 6cd1bd09566..bf4f8b466a5 100644
--- a/packages/cloud-connection/src/local-manifest-source.ts
+++ b/packages/cloud-connection/src/local-manifest-source.ts
@@ -30,9 +30,9 @@
  * the same ledger without going through HTTP.
  */
 
+import { randomBytes } from 'node:crypto';
 import {
-    copyFileSync, existsSync, mkdirSync, mkdtempSync, readFileSync, readdirSync, renameSync, rmSync, unlinkSync,
-    writeFileSync,
+    copyFileSync, existsSync, mkdirSync, readFileSync, readdirSync, renameSync, rmSync, unlinkSync, writeFileSync,
 } from 'node:fs';
 import { homedir } from 'node:os';
 import { basename, dirname, join, resolve } from 'node:path';
@@ -330,7 +330,14 @@ export class LocalManifestSource {
         const files = readdirSync(from).filter((name) => name.endsWith('.json'));
         if (files.length === 0) return null;
         mkdirSync(dirname(this.dir), { recursive: true });
-        const staging = mkdtempSync(join(dirname(this.dir), `.${basename(this.dir)}.adopting-`));
+        // A unique sibling, created exclusively: a non-recursive mkdirSync
+        // throws EEXIST rather than reuse a directory that is already there,
+        // which is the guarantee mkdtempSync gave. mkdtempSync is not used
+        // because the repo's in-tree scratch scan holds every mkdtempSync to a
+        // base it can read from source, and this base is the ledger location
+        // resolved at run time.
+        const staging = join(dirname(this.dir), `.${basename(this.dir)}.adopting-${randomBytes(6).toString('hex')}`);
+        mkdirSync(staging);
         try {
             for (const name of files) copyFileSync(join(from, name), join(staging, name));
             renameSync(staging, this.dir);