diff --git a/test/integration/fresh-mesh.test.ts b/test/integration/fresh-mesh.test.ts
index 2c7198b..b5b524b 100644
--- a/test/integration/fresh-mesh.test.ts
+++ b/test/integration/fresh-mesh.test.ts
@@ -138,6 +138,22 @@ async function must(machine: string, command: string, timeoutMs?: number): Promi
 async function mesh(command: string, timeoutMs?: number): Promise<string> {
   return must(CONTROL, `docker exec mesh-control /mesh-control ${command}`, timeoutMs);
 }
+
+/**
+ * Register a module from a manifest on this workstation.
+ *
+ * **The control plane runs in a container, so a file on the machine is not a file it can open.**
+ * Pushing the manifest to the machine and naming that path got `no such file or directory` from
+ * inside mesh-control, which is correct and was briefly mistaken for a missing manifest. It is
+ * copied the last step of the way with `docker cp`.
+ */
+async function registerModule(module: string, manifest: string): Promise<string> {
+  assert.ok(existsSync(manifest), `no manifest for ${module} at ${manifest}`);
+  const onMachine = `/tmp/${module}.json`;
+  await push(instanceId, CONTROL, manifest, onMachine);
+  await must(CONTROL, `docker cp ${onMachine} mesh-control:${onMachine}`);
+  return mesh(`module add ${onMachine}`);
+}
 function tokenFrom(said: string): string {
   const found = said.split("\n").map((l) => l.trim()).find((l) => l.length > 100 && !l.includes(" "));
   assert.ok(found, `no token in:\n${said}`);
@@ -250,12 +266,15 @@ before(async () => {
   // machine, published into the mesh's own registry.
   await step("the mesh builds the shared base from source",
     "three machines join it across the household gateway", async () => {
-    assert.ok(existsSync(baseManifest),
-      `no manifest for the shared base at ${baseManifest} — set MESH_LAB_BASE_MANIFEST`);
-    await push(instanceId, CONTROL, baseManifest, `/tmp/${BASE.module}.json`);
     // Registered from the manifest the builder will also read, so what the mesh holds and what it
     // builds are the same description of the same module.
-    await mesh(`module add /tmp/${BASE.module}.json`).catch(() => {});
+    //
+    // **Not swallowed.** This call used to end in `.catch(() => {})`, on the reasoning that the
+    // base might already be known. It hid a real failure — the manifest was being named at a path
+    // inside a container that had never seen it — and the step passed anyway, because a base with
+    // nothing to stand on builds whether or not the mesh has a record of it. The next step, which
+    // needs that record, is where it surfaced.
+    await registerModule(BASE.module, baseManifest);
     const built = await mesh(
       `build ${forgeUrl(BASE.repo)} --ref ${buildRef} --wait 1200s`, 1_500_000);
     assert.doesNotMatch(built, /failed/i, built);
@@ -265,10 +284,7 @@ before(async () => {
   // ---- 4. AND A MODULE STANDING ON IT ---------------------------------------------------------
   await step("the mesh builds a module standing on that base",
     "the mesh builds the shared base from source", async () => {
-    const manifest = resolve(catalogDir, MODULE.module, "module.json");
-    assert.ok(existsSync(manifest), `no manifest at ${manifest}`);
-    await push(instanceId, CONTROL, manifest, `/tmp/${MODULE.module}.json`);
-    await mesh(`module add /tmp/${MODULE.module}.json`);
+    await registerModule(MODULE.module, resolve(catalogDir, MODULE.module, "module.json"));
     const built = await mesh(
       `build ${forgeUrl(MODULE.repo)} --path ${MODULE.path} --ref ${buildRef} --wait 1200s`,
       1_500_000);