chore(core): Log npm output when the sandbox workspace link install fails (#40591)

Co-authored-by: Claude Opus 5.5 <[email protected]>

packages/@n8n/instance-ai/src/workspace/__tests__/sandbox-setup.test.ts

@@ -847,6 +847,87 @@ describe('setupSandboxWorkspace', () => {
 			'/workspace',
 		);
 	});
+
+	it('reports the install output when the tarball install fails', async () => {
+		const packSandboxLinkedWorkspacePackages = vi.fn().mockResolvedValue([
+			{
+				filename: 'workflow-sdk.tgz',
+				tarball: Buffer.from('sdk'),
+				version: '1.0.0',
+				packageName: '@n8n/workflow-sdk',
+				packagePath: '/host/sdk',
+			},
+		]);
+		const npmError = 'npm error notarget No matching version found for [email protected].';
+		const runInSandbox: RunInSandboxMock = vi
+			.fn<
+				(
+					...args: [SandboxWorkspace, string, string?]
+				) => Promise<{ exitCode: number; stdout: string; stderr: string }>
+			>()
+			// Daytona returns all command output in stdout.
+			.mockResolvedValue({ exitCode: 1, stdout: npmError, stderr: '' });
+		const linkWorkspaceSdkIfEnabled = await loadLinkWorkspaceSdkWithMocks(
+			packSandboxLinkedWorkspacePackages,
+			runInSandbox,
+		);
+		const workspace = {
+			filesystem: { provider: 'daytona', writeFile: vi.fn(async () => {}) },
+			sandbox: {},
+		} as unknown as SandboxWorkspace;
+		const logger = { error: vi.fn(), info: vi.fn(), warn: vi.fn(), debug: vi.fn() };
+
+		await expect(linkWorkspaceSdkIfEnabled(workspace, '/workspace', logger)).rejects.toThrow(
+			`Failed to install workspace package tarballs (exit code 1): ${npmError}`,
+		);
+		expect(logger.error).toHaveBeenCalledWith(
+			'Failed to link workspace packages into sandbox',
+			expect.objectContaining({
+				exitCode: 1,
+				command: expect.stringContaining(
+					"npm install '/workspace/workflow-sdk.tgz' --no-save --force",
+				),
+				output: npmError,
+			}),
+		);
+	});
+
+	it('keeps the end of long install output with stderr last', async () => {
+		const packSandboxLinkedWorkspacePackages = vi.fn().mockResolvedValue([
+			{
+				filename: 'workflow-sdk.tgz',
+				tarball: Buffer.from('sdk'),
+				version: '1.0.0',
+				packageName: '@n8n/workflow-sdk',
+				packagePath: '/host/sdk',
+			},
+		]);
+		const stdout = 'npm http fetch GET 200 https://registry.npmjs.org/pkg\n'.repeat(200);
+		const stderr = 'npm error notarget No matching version found for [email protected].';
+		const runInSandbox: RunInSandboxMock = vi
+			.fn<
+				(
+					...args: [SandboxWorkspace, string, string?]
+				) => Promise<{ exitCode: number; stdout: string; stderr: string }>
+			>()
+			.mockResolvedValue({ exitCode: 1, stdout, stderr });
+		const linkWorkspaceSdkIfEnabled = await loadLinkWorkspaceSdkWithMocks(
+			packSandboxLinkedWorkspacePackages,
+			runInSandbox,
+		);
+		const workspace = {
+			filesystem: { provider: 'local', writeFile: vi.fn(async () => {}) },
+			sandbox: {},
+		} as unknown as SandboxWorkspace;
+		const logger = { error: vi.fn(), info: vi.fn(), warn: vi.fn(), debug: vi.fn() };
+
+		await expect(linkWorkspaceSdkIfEnabled(workspace, '/workspace', logger)).rejects.toThrow(
+			stderr,
+		);
+		const { output } = logger.error.mock.calls[0][1] as { output: string };
+		const expectedTail = `${stdout}\n${stderr}`.trim().slice(-4000);
+		expect(output).toBe(`…${expectedTail}`);
+	});
 });
 describe('formatNodeCatalogLine', () => {
 	let formatNodeCatalogLine: FormatNodeCatalogLine;

packages/@n8n/instance-ai/src/workspace/sandbox-setup.ts

@@ -233,6 +233,15 @@ export const PACKAGE_JSON = buildPackageJson(
 
 let linkedPackagesPromise: Promise<WorkspacePackageTarball[] | null> | null = null;
 
+const MAX_INSTALL_OUTPUT_CHARS = 4000;
+
+function tailOutput(output: string): string {
+	const trimmed = output.trim();
+	return trimmed.length > MAX_INSTALL_OUTPUT_CHARS
+		? `…${trimmed.slice(-MAX_INSTALL_OUTPUT_CHARS)}`
+		: trimmed;
+}
+
 export async function linkWorkspaceSdkIfEnabled(
 	workspace: SandboxWorkspace,
 	root: string,
@@ -266,17 +275,20 @@ export async function linkWorkspaceSdkIfEnabled(
 	const tarballArgs = remotePaths
 		.map((remotePath) => `'${escapeSingleQuotes(remotePath)}'`)
 		.join(' ');
-	const install = await runInSandbox(
-		workspace,
-		`npm install ${tarballArgs} --no-save --force ${resolveNpmInstallFlags(workspace)}`,
-		root,
-	);
+	const command = `npm install ${tarballArgs} --no-save --force ${resolveNpmInstallFlags(workspace)}`;
+	const install = await runInSandbox(workspace, command, root);
 	if (install.exitCode !== 0) {
+		// Daytona returns all command output in stdout, so stderr alone is empty there.
+		// npm prints its error summary to stderr, so put stderr last and keep the end of the output.
+		const output = tailOutput([install.stdout, install.stderr].filter(Boolean).join('\n'));
 		logger.error('Failed to link workspace packages into sandbox', {
 			exitCode: install.exitCode,
-			stderr: install.stderr,
+			command,
+			output,
 		});
-		throw new Error(`Failed to install workspace package tarballs: ${install.stderr}`);
+		throw new Error(
+			`Failed to install workspace package tarballs (exit code ${install.exitCode}): ${output}`,
+		);
 	}
 
 	logger.info('Linked workspace packages into sandbox', {