🐞 CircleCI / GhA :: JavaScript heap out of memory

[frankleighintercom]

Describe the bug
We recently incorporated Sanity CMS into our NextJS Application using the npx sanity@latest init command.

It scaffolded out our CMS studio perfectly within the app router under (sanity)/studio/[[...tool]]/.

The app and studio run in dev perfectly and when building locally it's all good.

When we then go to build the app on a CI like Circle or with Github actions - we run into an error:

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory

To Reproduce

1. Create a nextJS application
2. run npx sanity@latest init
3. Let the cli tool do it's thing
4. Run a build from within circleCI or a Github action

Expected behavior

The build should not run out of memory.

Screenshots
If applicable, add screenshots to help explain your problem.

Which versions of Sanity are you using?

@sanity/cli (global)   3.89.0 (latest: 3.93.0)
@sanity/image-url       1.1.0 (up to date)
@sanity/ui            2.15.18 (latest: 2.16.2)
@sanity/vision         3.92.0 (latest: 3.93.0)
sanity                 3.89.0 (latest: 3.93.0)

What operating system are you using?
Docker

Which versions of Node.js / npm are you running?

9.8.1
v18.18.2

Additional context

"next": "15.3.0-canary.8",
"next-sanity": "^9.11.1",

It seems that either removing the instantiation of <NextSanity ... /> or removing the route created by sanity solves the issue but that means we can't have our CMS studio on our domain.

Full Github action logs:

> next build --no-lint
 ⚠ Linting is disabled.
⚠ No build cache found. Please configure build caching for faster rebuilds. Read more: https://nextjs.org/docs/messages/no-cache
Attention: Next.js now collects completely anonymous telemetry regarding usage.
This information is used to shape Next.js' roadmap and prioritize features.
You can learn more, including how to opt-out if you'd not like to participate in this anonymous program, by visiting the following URL:
https://nextjs.org/telemetry
   ▲ Next.js 15.3.0-canary.[8](https://github.com/intercom/fin-ai/actions/runs/15782394098/job/44490996655?pr=797#step:6:9)
   - Experiments (use with caution):
     ✓ viewTransition
     · clientTraceMetadata
   Creating an optimized production build ...
[@sentry/nextjs - Node.js] Warning: No auth token provided. Will not create release. Please set the `authToken` option. You can find information on how to generate a Sentry auth token here: https://docs.sentry.io/api/auth/
[@sentry/nextjs - Node.js] Warning: No auth token provided. Will not upload source maps. Please set the `authToken` option. You can find information on how to generate a Sentry auth token here: https://docs.sentry.io/api/auth/
[@sentry/nextjs - Node.js] Info: Sending telemetry data on issues and performance to Sentry. To disable telemetry, set `options.telemetry` to `false`.
<--- Last few GCs --->
[2182:0x2ec[9](https://github.com/intercom/fin-ai/actions/runs/15782394098/job/44490996655?pr=797#step:6:10)ea30]   135773 ms: Scavenge 1844.5 (2075.3) -> 1832.9 (2075.3) MB, 14.1 / 0.0 ms  (average mu = 0.275, current mu = 0.280) allocation failure; 
[2182:0x2ec9ea30]   135825 ms: Scavenge 1844.7 (2075.4) -> 1834.0 (2075.4) MB, 6.8 / 0.0 ms  (average mu = 0.275, current mu = 0.280) allocation failure; 
[2182:0x2ec9ea30]   135894 ms: Scavenge 1849.9 (2077.7) -> 1838.6 (2077.7) MB, 6.1 / 0.0 ms  (average mu = 0.275, current mu = 0.280) allocation failure; 
<--- JS stacktrace --->
FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory
 1: 0xb85bc0 node::Abort() [node]
 2: 0xa94834  [node]
 3: 0xd66d[10](https://github.com/intercom/fin-ai/actions/runs/15782394098/job/44490996655?pr=797#step:6:11) v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, bool) [node]
 4: 0xd670b7 v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, bool) [node]
 5: 0xf447c5  [node]
 6: 0xf456c8 v8::internal::Heap::RecomputeLimits(v8::internal::GarbageCollector) [node]
 7: 0xf55bd3  [node]
 8: 0xf56a48 v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [node]
 9: 0xf313ae v8::internal::HeapAllocator::AllocateRawWithLightRetrySlowPath(int, v8::internal::AllocationType, v8::internal::AllocationOrigin, v8::internal::AllocationAlignment) [node]
10: 0xf32777 v8::internal::HeapAllocator::AllocateRawWithRetryOrFailSlowPath(int, v8::internal::AllocationType, v8::internal::AllocationOrigin, v8::internal::AllocationAlignment) [node]
[11](https://github.com/intercom/fin-ai/actions/runs/15782394098/job/44490996655?pr=797#step:6:12): 0xf1394a v8::internal::Factory::NewFillerObject(int, v8::internal::AllocationAlignment, v8::internal::AllocationType, v8::internal::AllocationOrigin) [node]
[12](https://github.com/intercom/fin-ai/actions/runs/15782394098/job/44490996655?pr=797#step:6:13): 0x12d8caf v8::internal::Runtime_AllocateInYoungGeneration(int, unsigned long*, v8::internal::Isolate*) [node]
13: 0x1705b39  [node]
Aborted (core dumped)
 ELIFECYCLE  Command failed with exit code [13](https://github.com/intercom/fin-ai/actions/runs/15782394098/job/44490996655?pr=797#step:6:14)4.
Error: Process completed with exit code 134.

The action itself:

name: Test

on:
  push:
    branches: [poc/sanity-cms-merge-styles]
  pull_request:
    branches: [poc/sanity-cms-merge-styles]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: "18.18.2"

      - name: Install PNPM
        run: |
          sudo corepack enable
          corepack prepare pnpm@9.12.3 --activate
      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Build
        run: pnpm run build

app/(sanity)/studio/[[...tool]]/page.tsx

/**
 * This route is responsible for the built-in authoring environment using Sanity Studio.
 * All routes under your studio path is handled by this file using Next.js' catch-all routes:
 * https://nextjs.org/docs/routing/dynamic-routes#catch-all-routes
 *
 * You can learn more about the next-sanity package here:
 * https://github.com/sanity-io/next-sanity
 */
import { NextStudio } from "next-sanity/studio";

export { metadata, viewport } from "next-sanity/studio";

import config from "../../../../../sanity.config";

export default function StudioPage() {
  return <NextStudio config={config} />;
}

sanity.config

"use client";

/**
 * This configuration is used to for the Sanity Studio that's mounted on the `/app/studio/[[...tool]]/page.tsx` route
 */

import { visionTool } from "@sanity/vision";
import { structureTool } from "sanity/structure";
import { defineConfig } from "sanity";
import { graphiQLTool } from "sanity-plugin-graphiql";
// Go to https://www.sanity.io/docs/api-versioning to learn how API versioning works
import { apiVersion, dataset, projectId } from "./src/sanity/env";
import { schema } from "./src/sanity/schemaTypes";
import { structure } from "./src/sanity/structure";

export default defineConfig({
  basePath: "/studio",
  projectId,
  dataset,
  // Add and edit the content schema in the './sanity/schemaTypes' folder
  schema,
  plugins: [
    structureTool({ structure }),
    // Vision is for querying with GROQ from inside the Studio
    // https://www.sanity.io/docs/the-vision-plugin
    visionTool({ defaultApiVersion: apiVersion }),
    // graphiQLTool({
    //   apiVersion: "2021-10-21",
    // }),
  ],
});

This error is causing a complete blockage of our ability to encorporate a CMS into our application (the way we want to)

Alternatively we can have the CMS run on a separate server BUT this plugin should already enable us to have it live on the same domain...

[frankleighintercom]

├ ○ /studio/[[...tool]]                  1.48 MB        1.72 MB

SanityStudio & StudioProvider are absolutely MASSIVE