diff --git a/packages/cli/src/managed-python-runtime.test.ts b/packages/cli/src/managed-python-runtime.test.ts
index 35691e51..b63b6c19 100644
--- a/packages/cli/src/managed-python-runtime.test.ts
+++ b/packages/cli/src/managed-python-runtime.test.ts
@@ -70,6 +70,19 @@ describe('managedPythonRuntimeLayout', () => {
     expect(layout.assetManifestPath).toBe('/repo/packages/cli/assets/python/manifest.json');
   });
 
+  it('honors KTX_RUNTIME_ROOT before platform defaults', () => {
+    const layout = managedPythonRuntimeLayout({
+      cliVersion: '0.2.0',
+      platform: 'darwin',
+      env: { KTX_RUNTIME_ROOT: '/tmp/ktx-runtime' },
+      homeDir: '/Users/alex',
+      assetDir: '/repo/packages/cli/assets/python',
+    });
+
+    expect(layout.runtimeRoot).toBe('/tmp/ktx-runtime');
+    expect(layout.versionDir).toBe('/tmp/ktx-runtime/0.2.0');
+  });
+
   it('honors XDG_DATA_HOME on Linux', () => {
     const layout = managedPythonRuntimeLayout({
       cliVersion: '0.2.0',
diff --git a/packages/cli/src/managed-python-runtime.ts b/packages/cli/src/managed-python-runtime.ts
index 155b44e4..e78e8a76 100644
--- a/packages/cli/src/managed-python-runtime.ts
+++ b/packages/cli/src/managed-python-runtime.ts
@@ -119,6 +119,9 @@ function defaultAssetDir(): string {
 }
 
 function runtimeRootFor(input: Required<Pick<ManagedPythonRuntimeLayoutOptions, 'platform' | 'env' | 'homeDir'>>): string {
+  if (input.env.KTX_RUNTIME_ROOT) {
+    return input.env.KTX_RUNTIME_ROOT;
+  }
   if (input.platform === 'darwin') {
     return join(input.homeDir, 'Library', 'Application Support', 'kaelio', 'ktx', 'runtime');
   }
diff --git a/scripts/package-artifacts.mjs b/scripts/package-artifacts.mjs
index c3a339a1..8f38cf0b 100644
--- a/scripts/package-artifacts.mjs
+++ b/scripts/package-artifacts.mjs
@@ -569,6 +569,9 @@ export function npmSmokePackageJson(layout) {
     dependencies: {
       '@kaelio/ktx': `file:${layout.cliTarball}`,
     },
+    devDependencies: {
+      'better-sqlite3': '^12.6.2',
+    },
     pnpm: {
       onlyBuiltDependencies: ['better-sqlite3'],
     },
@@ -927,7 +930,7 @@ try {
   requireSuccessWithStderr(
     'ktx sl query first managed runtime install',
     slQuery,
-    /Installing KTX Python runtime \(core\) with uv[\\s\\S]*KTX Python runtime ready:/,
+    /Installing KTX Python runtime \\(core\\) with uv[\\s\\S]*KTX Python runtime ready:/,
   );
   requireOutput('ktx sl query first managed runtime install', slQuery, /"mode": "compile_only"/);
   requireOutput('ktx sl query first managed runtime install', slQuery, /orders/);
diff --git a/scripts/package-artifacts.test.mjs b/scripts/package-artifacts.test.mjs
index ef168a54..c4b36b09 100644
--- a/scripts/package-artifacts.test.mjs
+++ b/scripts/package-artifacts.test.mjs
@@ -513,9 +513,13 @@ describe('verification snippets', () => {
   it('pins the smoke project to the public package artifact', () => {
     const layout = packageArtifactLayout('/repo/ktx');
 
-    assert.deepEqual(npmSmokePackageJson(layout).dependencies, {
+    const packageJson = npmSmokePackageJson(layout);
+    assert.deepEqual(packageJson.dependencies, {
       '@kaelio/ktx': `file:${layout.cliTarball}`,
     });
+    assert.deepEqual(packageJson.devDependencies, {
+      'better-sqlite3': '^12.6.2',
+    });
   });
 
   it('exposes manifest verification as a package artifact command', async () => {
@@ -568,7 +572,7 @@ describe('verification snippets', () => {
     assert.match(source, /managed-runtime/);
     assert.match(source, /ktx runtime status missing/);
     assert.match(source, /runtimeStatusBefore\.kind, 'missing'/);
-    assert.match(source, /Installing KTX Python runtime \(core\) with uv/);
+    assert.ok(source.includes(String.raw`Installing KTX Python runtime \(core\) with uv`));
     assert.match(source, /KTX Python runtime ready:/);
     assert.match(source, /ktx runtime status ready/);
     assert.match(source, /runtimeStatusAfter\.kind, 'ready'/);