@sveltejs/adapter-vercel gets stuck in vercel CI (Exceeds the maximum size limit of 300mb)

[snorreks]

Describe the bug

When using @sveltejs/adapter-vercel it get stuck on Using @sveltejs/adapter-vercel in CI deployment:

...
✓ built in 19.18s
Run npm run preview to preview your production build locally.
> Using @sveltejs/adapter-vercel

After >15min it throws
The Serverless Function "![-]/0" is 545.09mb which exceeds the maximum size limit of 300mb.

I have used @sveltejs/adapter-vercel version 5.1.0 for over half a year and it worked then, now when I got back to the project and needed to fix a critical bug I can no longer deploy. I updated the version to 5.7.1, still the same issue. I tried with another adapter and that works. I am using nx and pnpm.

Reproduction

1. Install any version of @sveltejs/adapter-vercel
2. Build either on vercel CI
3. See that it get stuck in building process

Logs

[17:07:25.717] Running build in Washington, D.C., USA (East) – iad1
[17:07:25.732] Cloning github.com/Onboardr/onboardr (Branch: master, Commit: 4e3de20)
[17:07:25.880] Previous build caches not available
[17:07:26.805] Cloning completed: 1.073s
[17:07:27.492] Running "cd ../../../.. && bash pipelines/vercel-ignore-build-step.sh"
[17:07:27.713] VERCEL_GIT_COMMIT_REF: master
[17:07:27.714] VERCEL_ENV: production
[17:07:27.714] DISABLE_PREVIEW: 
[17:07:27.714] DISABLE_BUILD: 
[17:07:27.714] SKIP_CHECK: 1
[17:07:27.714] Skipping check
[17:07:27.714] 
[17:07:27.944] Running "vercel build"
[17:07:28.335] Vercel CLI 41.7.0
[17:07:28.447] > Detected Nx. Adjusting default settings...
[17:07:28.957] Detected `pnpm-lock.yaml` version 6 generated by pnpm@8.x
[17:07:28.958] Running "install" command: `cd ../../../.. && pnpm i`...
[17:07:29.595] Lockfile is up to date, resolution step is skipped
[17:07:29.836] Progress: resolved 1, reused 0, downloaded 0, added 0
[17:07:30.191] Packages: +2735
[17:07:30.191] ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
[17:07:30.845] Progress: resolved 2735, reused 0, downloaded 24, added 13
...
[17:07:48.248] Progress: resolved 2735, reused 0, downloaded 2730, added 2735, done
[17:07:49.263] .../node_modules/@firebase/util postinstall$ node ./postinstall.js
[17:07:49.264] .../node_modules/protobufjs postinstall$ node scripts/postinstall
[17:07:49.303] .../core-js@3.42.0/node_modules/core-js postinstall$ node -e "try{require('./postinstall')}catch(e){}"
[17:07:49.330] .../node_modules/@firebase/util postinstall: Done
[17:07:49.334] .../node_modules/protobufjs postinstall: Done
[17:07:49.354] .../core-js@3.42.0/node_modules/core-js postinstall: Done
[17:07:49.880] .../node_modules/@swc/core postinstall$ node postinstall.js
...
[17:08:30.751] �[32m✓ built in 19.18s�[39m
[17:08:30.751] Run �[1m�[36mnpm run preview�[22m�[39m to preview your production build locally.
[17:08:30.754] �[1m�[36m
[17:08:30.754] > Using @sveltejs/adapter-vercel�[22m�[39m

System Info

System:
    OS: Windows 11 10.0.26100
    CPU: (12) x64 Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
    Memory: 6.99 GB / 15.84 GB
  Binaries:
    Node: 20.14.0 - C:\Program Files\nodejs\node.EXE
    npm: 10.8.1 - C:\Program Files\nodejs\npm.CMD
    pnpm: 8.6.2 - ~\AppData\Roaming\npm\pnpm.CMD
    bun: 1.1.15 - ~\AppData\Roaming\npm\bun.CMD
  Browsers:
    Edge: Chromium (133.0.3065.59)
    Internet Explorer: 11.0.26100.1882
  npmPackages:
    @sveltejs/adapter-vercel: ^5.7.1 => 5.7.1
    @sveltejs/kit: ^2.5.0 => 2.20.8
    @sveltejs/vite-plugin-svelte: ^3.0.2 => 3.1.2
    svelte: ^4.2.9 => 4.2.19
    vite: ^6.3.4 => 6.3.4

Severity

blocking all usage of SvelteKit

Additional Information

package.json

{
	"name": "onboardr",
	"private": true,
	"type": "module",
	"browserslist": [
		">0.2%",
		"not dead",
		"not ie <= 11",
		"not op_mini all"
	],
	"scripts": {
		"affected": "nx affected",
		"affected:apps": "nx affected:apps",
		"affected:build": "nx affected:build",
		"affected:build-ci": "nx affected --target=build-ci",
		"affected:dep-graph": "nx affected:dep-graph",
		"affected:lint": "nx workspace-lint && nx affected --target=stylelint && nx affected:lint",
		"affected:lint-ci": "nx workspace-lint && nx affected --target=stylelint-ci && nx affected --target=lint-ci",
		"affected:test": "nx affected:test --watch=false --browsers Chromium",
		"affected:test-ci": "nx affected:test --code-coverage --watch=false --browsers ChromiumNoSandbox",
		"e2e": "nx e2e $APP",
		"e2e:no-serve": "nx e2e $APP --configuration=no-serve",
		"e2e:only-tag": "TAGS=@only npm run e2e:no-serve --retry=0",
		"dep-graph": "nx dep-graph",
		"format": "DISABLE_V8_COMPILE_CACHE=1 nx format:write",
		"format:check": "nx format:check",
		"format:write": "nx format:write",
		"format:write:all": "prettier --write \"**/*.{svelte,ts}\"",
		"lint": "nx run-many --all --target=lint --exclude=mailvideo-pwa,mailvideo-share,mailvideo-admin,mailvideo-chrome",
		"lint:localekey": "nx run-many --all --target=lint --projects=tag:scope:localekey --exclude=localekey-pwa",
		"lint:mailvideo": "nx run-many --all --target=lint --projects=tag:scope:mailvideo --exclude=mailvideo-pwa,mailvideo-share,mailvideo-admin,mailvideo-chrome",
		"lint:all": "nx run-many --all --target=lint",
		"validate": "nx run-many --all --target=validate",
		"validate:localekey": "nx run-many --projects=tag:scope:localekey --target=validate",
		"validate:mailvideo": "nx run-many --projects=tag:scope:mailvideo --target=validate",
		"nx": "nx",
		"start": "nx serve $APP",
		"test": "nx test $APP --code-coverage --browsers Chromium",
		"update": "nx migrate latest",
		"workspace-generator": "nx workspace-generator",
		"storybook": "pnpm nx storybook shared-frontend-storybook",
		"storybook:test": "pnpm nx build:test shared-frontend-storybook",
		"storybook:build": "pnpm nx build:storybook shared-frontend-storybook",
		"storybook:deploy": "chromatic --project-token=30e95e325c51 -b storybook:build -o dist/storybook",
		"storybook:deploy:skip-tests": "pnpm storybook:deploy --skip",
		"preinstall": "npx only-allow pnpm",
		"analyze": "npx cloc --exclude-dir=node_modules,dist,package.json,pnpm-lock.yaml,.svelte-kit,tmp,.vercel .",
		"postinstall": "patch-package"
	},
	"devDependencies": {
		"@astrojs/sitemap": "^3.0.5",
		"@astrojs/tailwind": "^5.1.0",
		"@astrojs/vercel": "^7.0.2",
		"@aws-sdk/middleware-signing": "^3.502.0",
		"@commitlint/cli": "^18.6.0",
		"@commitlint/config-conventional": "^18.6.0",
		"@crxjs/vite-plugin": "2.0.0-beta.18",
		"@faker-js/faker": "^8.4.0",
		"@firebase/app-compat": "^0.2.26",
		"@firebase/auth": "^1.5.1",
		"@firebase/auth-compat": "^0.5.1",
		"@firebase/auth-types": "^0.12.0",
		"@firebase/rules-unit-testing": "^3.0.1",
		"@fontsource-variable/inter": "^5.0.16",
		"@google-cloud/firestore": "^7.2.0",
		"@nrwl/nx-cloud": "^16.5.2",
		"@nx/devkit": "^17.3.0",
		"@nx/eslint-plugin": "^17.3.0",
		"@nx/js": "^17.3.0",
		"@nx/linter": "^17.3.0",
		"@nx/node": "^17.3.0",
		"@nx/storybook": "^17.3.0",
		"@nx/workspace": "^17.3.0",
		"@originjs/vite-plugin-commonjs": "^1.0.3",
		"@sentry/cli": "2.22.2",
		"@sentry/node": "^7.98.0",
		"@sentry/serverless": "^7.98.0",
		"@sentry/sveltekit": "^7.98.0",
		"@sentry/types": "^7.98.0",
		"@storybook/addon-essentials": "8.0.0-alpha.9",
		"@storybook/addon-interactions": "8.0.0-alpha.9",
		"@storybook/jest": "^0.2.3",
		"@storybook/manager-api": "8.0.0-alpha.9",
		"@storybook/svelte": "8.0.0-alpha.9",
		"@storybook/svelte-vite": "8.0.0-alpha.9",
		"@storybook/test-runner": "^0.16.0",
		"@storybook/testing-library": "^0.2.2",
		"@storybook/theming": "8.0.0-alpha.9",
		"@storybook/types": "8.0.0-alpha.9",
		"@sveltejs/kit": "^2.5.0",
		"@sveltejs/vite-plugin-svelte": "^3.0.2",
		"@swc/core": "^1.3.107",
		"@testing-library/dom": "^9.3.4",
		"@testing-library/svelte": "^4.1.0",
		"@types/aws-lambda": "^8.10.133",
		"@types/chrome": "^0.0.259",
		"@types/common-tags": "^1.8.4",
		"@types/cookie": "^0.6.0",
		"@types/cross-spawn": "^6.0.6",
		"@types/eslint": "^8.56.2",
		"@types/file-saver": "^2.0.7",
		"@types/fluent-ffmpeg": "^2.1.24",
		"@types/fs-extra": "^11.0.4",
		"@types/humanize-duration": "^3.27.4",
		"@types/intercom-web": "^2.8.24",
		"@types/jsonwebtoken": "^9.0.5",
		"@types/node": "^20.11.10",
		"@types/w3c-image-capture": "^1.0.10",
		"@typescript-eslint/eslint-plugin": "^6.20.0",
		"@typescript-eslint/parser": "^6.20.0",
		"@typescript-eslint/typescript-estree": "^6.20.0",
		"@vavite/node-loader": "^4.0.2",
		"@vite-pwa/sveltekit": "^0.3.0",
		"astro": "^4.2.6",
		"astro-icon": "^1.0.4",
		"astro-navbar": "^2.3.0",
		"astro-seo": "^0.8.0",
		"astro-windi": "^0.0.2",
		"autoprefixer": "^10.4.17",
		"chromatic": "^10.6.1",
		"commitizen": "^4.3.0",
		"cookie": "^0.6.0",
		"core-js": "^3.35.1",
		"cross-env": "^7.0.3",
		"cz-customizable": "^7.0.0",
		"dotenv": "^16.4.1",
		"esbuild": "^0.20.0",
		"esbuild-plugin-alias": "^0.2.1",
		"eslint": "^8.56.0",
		"eslint-config-google": "^0.14.0",
		"eslint-config-prettier": "^9.1.0",
		"eslint-import-resolver-node": "^0.3.9",
		"eslint-plugin-import": "^2.29.1",
		"eslint-plugin-no-floating-promise": "^1.0.2",
		"eslint-plugin-prettier": "^5.1.3",
		"eslint-plugin-sort": "^2.11.0",
		"eslint-plugin-sort-class-members": "^1.19.0",
		"eslint-plugin-storybook": "^0.6.15",
		"eslint-plugin-svelte": "^2.35.1",
		"firebase-functions-test": "^3.1.1",
		"firebase-tools": "^13.1.0",
		"fs-extra": "^11.2.0",
		"hubspot": "^2.3.14",
		"jest": "^29.7.0",
		"jest-mock": "^29.7.0",
		"jsdom": "^24.0.0",
		"lefthook": "^1.6.1",
		"libphonenumber-js": "^1.10.54",
		"localekey": "^0.0.3",
		"nx": "^17.3.0",
		"nx-cloud": "^16.5.2",
		"nx-cloud-functions-deployer": "^2.5.4",
		"nx-vercel-utils": "^0.1.0",
		"patch-package": "^8.0.0",
		"prettier": "^3.2.4",
		"prettier-plugin-jsdoc": "^1.3.0",
		"prettier-plugin-svelte": "^3.1.2",
		"prettier-plugin-tailwindcss": "^0.5.11",
		"react": "^18.2.0",
		"react-dom": "^18.2.0",
		"rollup-plugin-visualizer": "^5.12.0",
		"sass": "^1.70.0",
		"sharp": "^0.33.2",
		"storybook": "8.0.0-alpha.9",
		"style-loader": "^3.3.4",
		"stylelint": "^16.2.0",
		"stylelint-checkstyle-formatter": "^0.1.2",
		"stylelint-config-prettier": "^9.0.5",
		"stylelint-config-standard": "^36.0.0",
		"stylelint-order": "^6.0.4",
		"svelte": "^4.2.9",
		"svelte-check": "^3.6.3",
		"svelte-preprocess": "^5.1.3",
		"tslib": "^2.6.2",
		"tsup": "^8.0.1",
		"tsx": "^4.7.0",
		"typescript": "^5.3.3",
		"vercel": "^33.4.0",
		"vite": "^6.3.4",
		"vite-plugin-iso-import": "^1.1.0",
		"vite-plugin-pwa": "^0.17.5",
		"vite-plugin-windicss": "^1.9.3",
		"vite-tsconfig-paths": "^4.3.1",
		"vitest": "^1.2.2",
		"windicss": "^3.5.6",
		"windicss-analysis": "^0.3.5",
		"workbox-core": "^7.0.0",
		"workbox-precaching": "^7.0.0",
		"workbox-window": "^7.0.0",
		"xhr-shim": "^0.1.3"
	},
	"dependencies": {
		"@aws-sdk/client-lambda": "^3.502.0",
		"@aws-sdk/client-s3": "^3.502.0",
		"@aws-sdk/lib-storage": "^3.502.0",
		"@aws-sdk/s3-request-presigner": "^3.502.0",
		"@sentry/integrations": "^7.98.0",
		"@sentry/svelte": "^7.98.0",
		"@slack/webhook": "^7.0.2",
		"@stripe/stripe-js": "^2.4.0",
		"@sveltejs/adapter-vercel": "^5.7.1",
		"axios": "^1.6.7",
		"clsx": "^2.1.0",
		"color2k": "^2.0.3",
		"common-tags": "^1.8.2",
		"country-region-data": "^3.0.0",
		"cropperjs": "^1.6.1",
		"date-picker-svelte": "^2.10.1",
		"dayjs": "^1.11.10",
		"detect-browser": "^5.3.0",
		"device-detector-js": "^3.0.3",
		"exceljs": "^4.4.0",
		"fast-fuzzy": "^1.12.0",
		"fast-safe-stringify": "^2.1.1",
		"file-saver": "^2.0.5",
		"firebase": "^10.7.2",
		"firebase-admin": "^12.0.0",
		"firebase-functions": "^4.6.0",
		"fluent-ffmpeg": "^2.1.2",
		"gpt3-tokenizer": "^1.1.5",
		"humanize-duration": "^3.31.0",
		"idb-keyval": "^6.2.1",
		"isbot": "^4.4.0",
		"jsonwebtoken": "^9.0.2",
		"jszip": "^3.10.1",
		"jwks-rsa": "^3.1.0",
		"meilisearch": "^0.37.0",
		"openai": "^4.26.0",
		"postmark": "^4.0.2",
		"stripe": "^14.14.0",
		"svelte-tel-input": "^3.3.9",
		"tailwindcss-themeable": "^1.3.0",
		"typesafe-i18n": "^5.26.2",
		"wavesurfer.js": "7.5.7",
		"webm-duration-fix": "^1.0.4",
		"winston": "^3.11.0",
		"zod": "^3.22.4"
	},
	"packageManager": "pnpm@8.6.2",
	"config": {
		"commitizen": {
			"path": "./node_modules/cz-customizable"
		},
		"cz-customizable": {
			"config": "cz-config.cjs"
		}
	}
}

svelte.config.js

import preprocess from 'svelte-preprocess';
import adapter from '@sveltejs/adapter-vercel';
import { dirname, resolve, join } from 'node:path';
import { fileURLToPath } from 'node:url';

const projectDirectory = dirname(fileURLToPath(import.meta.url));
const libsDirectory = resolve(projectDirectory, '../../../../libs');
/**
 * Get the absolute path from the root directory
 *
 * @param {string} path Relative path
 * @returns {string} Absolute path
 */
const toLibPath = (path) => join(libsDirectory, path);
/**
 * Get the absolute path from the src folder in the project directory
 *
 * @param {string} path Relative path
 * @returns {string} Absolute path
 */
const toSrcPath = (path) => join(projectDirectory, 'src', path);

/** @type {import('@sveltejs/kit').Config} */
const config = {
	kit: {
		adapter: adapter({
			// https://vercel.com/templates/svelte/sveltekit-edge-functions
			// edge: process.env.ENABLE_VC_BUILD === '1',
			// runtime: 'nodejs20.x',
		}),
		alias: {
			'$views/*': toSrcPath('lib/views'),
			'$components/*': toSrcPath('lib/components'),
			$i18n: toLibPath('mailvideo/frontend/i18n/src'),
			'$i18n/*': toLibPath('mailvideo/frontend/i18n/src'),
			$lib: toLibPath('lib'),
			'$lib/*': toSrcPath('lib'),
			$types: toSrcPath('lib/types'),
			$utils: toSrcPath('lib/utils'),
			'$utils/*': toSrcPath('lib/utils'),
			'@mailvideo/backend/admin/*': toLibPath(
				'mailvideo/backend/admin/src',
			),
			'@mailvideo/backend/ai/*': toLibPath('mailvideo/backend/ai/src'),
			'@mailvideo/backend/auth/*': toLibPath(
				'mailvideo/backend/auth/src',
			),
			'@mailvideo/backend/aws/*': toLibPath('mailvideo/backend/aws/src'),
			'@mailvideo/backend/configs/*': toLibPath(
				'mailvideo/backend/configs/src',
			),
			'@mailvideo/backend/crm/*': toLibPath('mailvideo/backend/crm/src'),
			'@mailvideo/backend/database/*': toLibPath(
				'mailvideo/backend/database/src',
			),
			'@mailvideo/backend/search/*': toLibPath(
				'mailvideo/backend/search/src',
			),
			'@mailvideo/backend/stripe/*': toLibPath(
				'mailvideo/backend/stripe/src',
			),
			'@mailvideo/backend/svelte-kit/*': toLibPath(
				'mailvideo/backend/svelte-kit/src',
			),
			'@mailvideo/backend/team/*': toLibPath(
				'mailvideo/backend/team/src',
			),
			'@mailvideo/backend/utils/*': toLibPath(
				'mailvideo/backend/utils/src',
			),
			'@mailvideo/backend/video/thumbnail/*': toLibPath(
				'mailvideo/backend/video/thumbnail/src',
			),
			'@mailvideo/backend/video/upload/*': toLibPath(
				'mailvideo/backend/video/upload/src',
			),
			'@mailvideo/constants': toLibPath('mailvideo/constants/src'),
			'@mailvideo/frontend/components': toLibPath(
				'mailvideo/frontend/components/src',
			),
			'@mailvideo/frontend/repositories': toLibPath(
				'mailvideo/frontend/repositories/src',
			),
			'@mailvideo/frontend/services': toLibPath(
				'mailvideo/frontend/services/src',
			),
			$services: toLibPath('mailvideo/frontend/services/src'),
			// NB: /$services/loader has to come before $services/* because of the wildcard
			'$services/loader': toLibPath(
				'mailvideo/frontend/services/src/loader',
			),
			'$services/base-frontend-class': toLibPath(
				'shared/frontend/services/src/base-frontend-class',
			),
			'$services/*': toLibPath('mailvideo/frontend/services/src/lib'),

			$routes: toLibPath(
				'shared/frontend/services/src/lib/router/routes',
			),
			$router: toLibPath(
				'shared/frontend/services/src/lib/router/router-utils',
			),

			'@mailvideo/frontend/utils': toLibPath(
				'mailvideo/frontend/utils/src',
			),
			'@mailvideo/frontend/video/add': toLibPath(
				'mailvideo/frontend/video/add/src',
			),
			'@mailvideo/frontend/video/recorder': toLibPath(
				'mailvideo/frontend/video/recorder/src',
			),
			'@mailvideo/frontend/video/view': toLibPath(
				'mailvideo/frontend/video/view/src',
			),
			'@mailvideo/mocks': toLibPath('mailvideo/mocks/src'),
			'@mailvideo/player': toLibPath(
				'mailvideo/frontend/video/player/src',
			),
			'@mailvideo/schemas': toLibPath('mailvideo/schemas/src'),
			'@mailvideo/types': toLibPath('mailvideo/types/src'),
			'@mailvideo/utils': toLibPath('mailvideo/utils/src'),
			'@shared/constants': toLibPath('shared/constants/src'),
			'@shared/frontend/services': toLibPath(
				'shared/frontend/services/src',
			),
			'@shared/frontend/services/*': toLibPath(
				'shared/frontend/services/src/lib',
			),
			'@shared/frontend/test': toLibPath('shared/frontend/test/src'),
			'@shared/frontend/utils': toLibPath('shared/frontend/utils/src'),
			'@shared/frontend/utils/*': toLibPath(
				'shared/frontend/utils/src/lib',
			),
			'@shared/mocks': toLibPath('shared/mocks/src'),
			'@shared/svelte': toLibPath('shared/frontend/svelte/src'),
			'@shared/svelte-kit': toLibPath('shared/frontend/svelte-kit/src'),
			'@shared/table': toLibPath('shared/frontend/table/src'),
			'@shared/schemas': toLibPath('shared/schemas/src'),
			'@shared/types': toLibPath('shared/types/src'),
			'@shared/utils': toLibPath('shared/utils/src'),
			'@shared/logger': toLibPath(
				'shared/utils/src/lib/logger/svelte-kit',
			),
			'@shared/backend/configs/*': toLibPath(
				'shared/backend/configs/src',
			),
			'@shared/backend/utils/*': toLibPath('shared/backend/utils/src'),
		},

		// inline all stylesheets smaller than 1kb
		inlineStyleThreshold: 1024,
	},
	preprocess: [
		preprocess({
			postcss: false,
			scss: {
				outputStyle: 'compressed',
			},
			typescript: true,
		}),
	],
};

export default config;

vite.config.ts

import { dirname, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import { visualizer } from 'rollup-plugin-visualizer';
import { defineConfig, type PluginOption, type UserConfig } from 'vite';
import { isoImport } from 'vite-plugin-iso-import';
import windiCSS from 'vite-plugin-windicss';
import { sveltekit } from '@sveltejs/kit/vite';

// import { sveltekitPWA } from '@vite-pwa/sveltekit';

const directory = dirname(fileURLToPath(import.meta.url));
const rootDirectory = resolve(directory, '../../../..');

export default defineConfig(({ mode }) => {
	const plugins: PluginOption[] = [
		windiCSS({
			config: './windi.config.ts',
		}),
		isoImport(),
	];

	plugins.push(sveltekit());

	if (mode === 'analyze') {
		plugins.push(
			visualizer({
				brotliSize: true,
				filename: 'dist/stats.html',
				gzipSize: true,
				open: true,
			}) as unknown as PluginOption,
		);
	}

	const config: UserConfig = {
		build: {
			sourcemap: false,
		},
		envPrefix: ['PUBLIC_'],
		plugins,
		server: {
			fs: {
				allow: [rootDirectory],
				deny: [
					'C:\\ProgramData', // Block access to ProgramData
					'C:\\Windows', // Block access to Windows
					'C:\\$Recycle.Bin', // Block access to Recycle Bin
				],
			},
			port: 7000,
		},
	};
	return config;
});

[snorreks]

I believe there is a bug with with nodeFileTrace from
import { nodeFileTrace } from '@vercel/nft';

in the @sveltejs/adapter-vercel package:

in node_modules/@sveltejs/adapter-vercel/index.js line 639 when I add this:

const traced = await nodeFileTrace([entry], { base, ignore: [
'/nix/store/',
'/node_modules/.cache/',
'.cache',
'/home/'
] });

it works locally.

I suspect that nodeFileTrace includes a lot of unnecessary files from the container that vercel is running on the cloud. Example it tried to add discord config file to the functions folder when I ran locally.

[pkat]

I've run into this same issue and been debugging this issue extensively (with the help of claude code) and wanted to share my findings and potential workaround, which I believe is working, but will continue to test and monitor.

Environment

• @sveltejs/adapter-vercel: 6.3.0
• @sveltejs/kit: 2.50.0
• pnpm: 10.28.1
• Vercel with ENABLE_EXPERIMENTAL_COREPACK=1
• Turborepo monorepo structure

The Problem

One of our apps in our monorepo app fails to deploy with:

Error: A Serverless Function has exceeded the unzipped maximum size of 250 MB.

Meanwhile, our other app (same monorepo, same adapter version, also sveltekit) deploys successfully.

Root Cause Analysis

I added debug logging to the adapter's create_function_bundle function to analyze what NFT was tracing:

const tracedArray = Array.from(traced.fileList);
const outsideProject = tracedArray.filter(f => !f.startsWith('vercel/path0/'));
console.log(`[NFT Debug] Traced files count: ${tracedArray.length}`);
console.log(`[NFT Debug] Files outside vercel/path0/: ${outsideProject.length}`);
console.log(`[NFT Debug] Sample:`, outsideProject.slice(0, 20));

Results:

[NFT Debug] Traced files count: 14598
[NFT Debug] Files outside vercel/path0/: 13933
[NFT Debug] Sample: [
  'uv/python_metadata.json',
  'node22/bin/node',
  'uv/python/bin/python3.14',
  'uv/python/bin/python3.13',
  'uv/python/versions/cpython-3.14.2-linux-x86_64-gnu/BUILD',
  ...
]

Key Finding: When base is set to / (the filesystem root), NFT traces Vercel's build environment system files:

• uv/ - Python installation (~13,000+ files)
• node22/ - Node.js installation
• .vercel/cache/corepack/ - pnpm installation (~476 files)

The project files are at vercel/path0/, but NFT follows symlinks/dependencies that resolve to paths outside this directory.

Why It Affects Some Apps But Not Others

The difference seems to be in the dependency graph complexity. Our app with the issue has dependencies that trigger NFT to trace more aggressively into these system paths (most significantly the flags library which has jose dependency), while the app without issue stays just under the limit.

Our Workaround

I'm patching the adapter to add an ignore callback:

const isOnVercel = entry.includes('/vercel/path0/');

const traced = await nodeFileTrace([entry], {
  base,
  ignore: (p) => {
    if (isOnVercel) {
      // Only keep files in vercel/path0/, exclude .vercel/cache/
      const isProjectFile = p.startsWith('vercel/path0/') || p.startsWith('/vercel/path0/');
      if (!isProjectFile) {
        return true; // ignore system files (uv/, node22/, etc)
      }
      if (p.includes('.vercel/cache/')) {
        return true; // ignore corepack cache
      }
      return false;
    }
    // Local builds: only filter /opt/, /usr/, /nix/
    return p.startsWith('/opt/') || p.startsWith('/usr/') || p.startsWith('/nix/');
  }
});

This reduced traced files from ~14,600 to ~700.

Suggested Fix

The adapter could:

1. Detect Vercel environment and scope NFT to only trace within the project directory
2. Add a default ignore pattern for common system paths and .vercel/cache/
3. Expose an ignore option in the adapter config for users to customize

Something like:

const isOnVercel = entry.startsWith('/vercel/path0/');
const projectRoot = isOnVercel ? 'vercel/path0/' : null;

const traced = await nodeFileTrace([entry], {
  base,
  ignore: (p) => {
    // Always ignore Vercel cache (corepack, etc)
    if (p.includes('.vercel/cache/')) return true;
    
    // On Vercel, only trace project files
    if (projectRoot && !p.startsWith(projectRoot) && !p.startsWith('/' + projectRoot)) {
      return true;
    }
    
    return false;
  }
});

Additional Context

• The issue seems more significant with Vercel's corepack support (ENABLE_EXPERIMENTAL_COREPACK=1), although I was having the issue even without it enabled and defaulting to pnpm v9.
• The corepack cache at .vercel/cache/corepack/home/v1/pnpm/ contains the full pnpm distribution
• NFT traces into this because pnpm resolves some dependencies through symlinks that eventually reach the corepack installation

[jioo]

Thank you for sharing this workaround, @pkat.

We were also encountering this error in Vercel CI:

Error: A Serverless Function has exceeded the unzipped maximum size of 250 MB. : https://vercel.link/serverless-function-size

---

We've applied your workaround using patch-package

1. Install patch-package:

   npm i -D patch-package

2. Add a postinstall script to your package.json:

   "scripts": {
     "postinstall": "patch-package"
   }

3. Create a file patches/@sveltejs+adapter-vercel+6.3.0.patch:

   diff --git a/node_modules/@sveltejs/adapter-vercel/index.js b/node_modules/@sveltejs/adapter-vercel/index.js
   index f54765d..5a7db4f 100644
   --- a/node_modules/@sveltejs/adapter-vercel/index.js
   +++ b/node_modules/@sveltejs/adapter-vercel/index.js
   @@ -661,7 +661,26 @@ async function create_function_bundle(builder, entry, dir, config) {
       let base = entry;
       while (base !== (base = path.dirname(base)));
   
   -	const traced = await nodeFileTrace([entry], { base });
   +	const isOnVercel = entry.includes('/vercel/path0/');
   +
   +	const traced = await nodeFileTrace([entry], {
   +		base,
   +		ignore: (p) => {
   +			if (isOnVercel) {
   +				// Only keep files in vercel/path0/, exclude .vercel/cache/
   +				const isProjectFile = p.startsWith('vercel/path0/') || p.startsWith('/vercel/path0/');
   +				if (!isProjectFile) {
   +					return true; // ignore system files (uv/, node22/, etc)
   +				}
   +				if (p.includes('.vercel/cache/')) {
   +					return true; // ignore corepack cache
   +				}
   +				return false;
   +			}
   +			// Local builds: only filter /opt/, /usr/, /nix/
   +			return p.startsWith('/opt/') || p.startsWith('/usr/') || p.startsWith('/nix/');
   +		}
   +	});
   
       /** @type {Map<string, string[]>} */
       const resolution_failures = new Map();

---

Environment

• @sveltejs/adapter-vercel: 6.3.0
• @sveltejs/kit: 2.50.0

[pkat]

@jioo Glad that it was helpful. I should've shared the full patch, but you got it.

For pnpm users, in your pnpm-workspace.yaml file you can reference the patch:

patchedDependencies:
  '@sveltejs/adapter-vercel@6.3.0': patches/@sveltejs__adapter-vercel@6.3.0.patch

with a patches/@sveltejs__adapter-vercel@6.3.0.patch file (same as above):

diff --git a/index.js b/index.js
--- a/index.js
+++ b/index.js
@@ -661,7 +661,33 @@
 	let base = entry;
 	while (base !== (base = path.dirname(base)));

-	const traced = await nodeFileTrace([entry], { base });
+	// See: https://github.com/sveltejs/kit/issues/13764
+	// Fix for pnpm monorepos on Vercel: NFT traces system paths when base is '/'
+	// Detect if we're on Vercel by checking the entry path
+	const isOnVercel = entry.includes('/vercel/path0/');
+
+	const traced = await nodeFileTrace([entry], {
+		base,
+		ignore: (p) => {
+			if (isOnVercel) {
+				// On Vercel: only keep files in vercel/path0/, exclude .vercel/cache/
+				const isProjectFile = p.startsWith('vercel/path0/') || p.startsWith('/vercel/path0/');
+				if (!isProjectFile) {
+					return true; // ignore system files (uv/, node22/, etc)
+				}
+				// Filter out .vercel/cache (corepack, etc)
+				if (p.includes('.vercel/cache/')) {
+					return true; // ignore
+				}
+				return false; // keep project files
+			}
+			// Local builds: only filter system directories
+			if (p.startsWith('/opt/') || p.startsWith('/usr/') || p.startsWith('/nix/')) {
+				return true;
+			}
+			return false;
+		}
+	});

 	/** @type {Map<string, string[]>} */
 	const resolution_failures = new Map();

@benmccann Is this issue something that could be prioritized for fixing? Thanks!

[teemingc]

I'm having difficulty reproducing the issue. My hunch is it's something to do with nx (which is present in both build logs). I've created a repository trying to reproduce this at https://github.com/teemingc/kit-13764 . It would be a great help if I could get some pointers on how to reproduce this

[jioo]

@teemingc This is our exact json dependencies and devDependencies used in our Sveltekit project deployed on Vercel. I hope this helps.

---

Vercel Settings (Build and Deployment)

• Framework Settings: Sveltekit
• Node.js Version: 24.x

---

package.json

"devDependencies": {
	"@playwright/test": "^1.49.1",
	"@sveltejs/adapter-vercel": "^5.7.1",
	"@sveltejs/kit": "^2.16.0",
	"@sveltejs/vite-plugin-svelte": "^5.0.0",
	"@tailwindcss/forms": "^0.5.9",
	"@tailwindcss/postcss": "^4.0.15",
	"@tailwindcss/typography": "^0.5.15",
	"@tailwindcss/vite": "^4.0.0",
	"autoprefixer": "^10.4.21",
	"prettier": "^3.4.2",
	"prettier-plugin-svelte": "^3.3.3",
	"prettier-plugin-tailwindcss": "^0.6.11",
	"svelte": "^5.0.0",
	"tailwindcss": "^4.0.0",
	"vite": "^6.0.0",
	"vitest": "^3.0.9"
},
"dependencies": {
	"@fortawesome/fontawesome-free": "^6.7.2",
	"aws-sdk": "^2.1692.0",
	"axios": "^1.8.3",
	"bcryptjs": "^3.0.2",
	"cookie": "^1.0.2",
	"daisyui": "^5.0.0",
	"is-mobile": "^5.0.0",
	"jsonwebtoken": "^9.0.2",
	"luxon": "^3.5.0",
	"mysql2": "^3.13.0",
	"qrcode": "^1.5.4"
}

[teemingc]

Unfortunately, I'm still unable to reproduce it. If it's possible, try making a copy of your project and trim it down by deleting routes/dependencies one at a time and deploying it until it no longer crashes the build. This should make it easier to discover the minimal cause.

[pkat]

Unfortunately, I'm still unable to reproduce it. If it's possible, try making a copy of your project and trim it down by deleting routes/dependencies one at a time and deploying it until it no longer crashes the build. This should make it easier to discover the minimal cause.

Hi @teemingc,

I was able to reproduce this into an example repo: https://github.com/pkat/svelte-vercel-adapter-issue

I've traced this to a specific interaction between three systems: SvelteKit's $env/static/private, Vite's chunk splitting, and @vercel/nft's AST analysis.

The Chain

1. $env/static/private inlines ALL process.env as string constants

SvelteKit compiles every environment variable into a server chunk at build time:

const NODE = "/node22/bin/node";
const PATH = "/uv/bin:/node22/bin:/usr/local/bin:...";
const HOME = "/vercel";
// ... every process.env variable

2. Vite merges the env chunk into a shared config chunk

When multiple server-side routes import a shared module that uses $env/static/private, Vite's chunk splitting merges them into a single chunk, creating a namespace object with shorthand properties:

const _private = Object.freeze(Object.defineProperty({
  __proto__: null,
  NODE,     // shorthand property
  PATH,     // shorthand property
  HOME,     // shorthand property
  // ...
}, Symbol.toStringTag, { value: "Module" }));

This only happens when there are enough consumers of the shared module to trigger Vite's chunk merging. A simple app with one route keeps $env/static/private in its own chunk with plain export { NODE, ... } specifiers.

3. @vercel/nft treats shorthand properties as identifier reads

NFT's isIdentifierRead() in ast-helpers.js returns true for Property nodes (shorthand properties) but false for ExportSpecifier nodes:

// NFT IGNORES this — isIdentifierRead returns false for ExportSpecifier
export { NODE };

// NFT READS this — isIdentifierRead returns true for Property
{ NODE }  // inside Object.freeze(...)

When NFT reads the identifier NODE, it resolves the bound value "/node22/bin/node" and traces that as a file path. On Vercel's build environment, this sweeps in system directories like /proc, /pnpm10, /node24, etc., producing 250MB+ bundles.

Key Diagnostic

The .vc-config.json handler path is the tell. A healthy build has:

{ "handler": "index.js" }

An affected build has:

{ "handler": "vercel/path0/apps/my-app/.svelte-kit/vercel-tmp/index.js" }

The vercel/path0/ prefix appears because system files in the trace cause the common ancestor calculation to drop to /.

If you deploy this "app-with-flags" app to build on Vercel, you'll see in the build logs (via the postbuild script) the references to the system directories, as well as after the build, you'll see the function sizes are 53.2 MB.

app-with-flags:build: ========================================
app-with-flags:build:   NFT Bundle Analysis (post-build)
app-with-flags:build: ========================================
app-with-flags:build: 
app-with-flags:build: 
app-with-flags:build: Function: ![-]/catchall.func
app-with-flags:build: --------------------------------------------------
app-with-flags:build:   Handler: vercel/path0/apps/app-with-flags/.svelte-kit/vercel-tmp/index.js
app-with-flags:build:   Runtime: nodejs22.x
app-with-flags:build:   ⚠ Handler contains "vercel/path0" — common ancestor likely dropped to /
app-with-flags:build:   Total files: 689
app-with-flags:build:   Total size: 136.3 MB
app-with-flags:build: 
app-with-flags:build:   Top-level directories:
app-with-flags:build:     node24: 1 files, 115.5 MB
app-with-flags:build:     usr: 120 files, 16.5 MB
app-with-flags:build:     vercel: 565 files, 4.2 MB
app-with-flags:build:     .vc-config.json: 1 files, 260 B
app-with-flags:build:     package.json: 1 files, 17 B
app-with-flags:build:     proc: 1 files, 0 B
app-with-flags:build: 
app-with-flags:build:   ⚠ SYSTEM DIRECTORIES DETECTED IN BUNDLE:
app-with-flags:build:     node24: 1 files, 115.5 MB
app-with-flags:build:     usr: 120 files, 16.5 MB
app-with-flags:build:     proc: 1 files, 0 B
app-with-flags:build: 
app-with-flags:build:   This confirms the NFT tracing bug — system files are being bundled.
app-with-flags:build:   See: https://github.com/sveltejs/kit/issues/13764
app-with-flags:build: 
app-with-flags:build: ========================================

Reproduction

Minimal reproduction repo: https://github.com/pkat/svelte-vercel-adapter-issue

• app-simple — no flags/sveltekit, one route → builds clean (~1 MB)
• app-with-flags — uses flags/sveltekit, multiple routes importing a shared Config → triggers the bug

The flags/sveltekit library's tryGetSecret() does a dynamic import("$env/static/private") internally, which combined with the app's own import * as env from '$env/static/private' in a shared Config module creates enough import graph complexity for Vite to merge the chunks.

Workaround

A patch that adds an ignore callback to nodeFileTrace resolves the issue:

--- a/index.js
+++ b/index.js
@@ -661,7 +661,18 @@
 	let base = entry;
 	while (base !== (base = path.dirname(base)));

-	const traced = await nodeFileTrace([entry], { base });
+	const isOnVercel = entry.includes('/vercel/path0/');
+
+	const traced = await nodeFileTrace([entry], {
+		base,
+		ignore: (p) => {
+			if (isOnVercel) {
+				const isProjectFile = p.startsWith('vercel/path0/') || p.startsWith('/vercel/path0/');
+				if (!isProjectFile) return true;
+				if (p.includes('.vercel/cache/')) return true;
+				return false;
+			}
+			return false;
+		}
+	});

Suggested Fix

The fix could live in either @sveltejs/adapter-vercel or @vercel/nft:

• adapter-vercel: Add a default ignore callback that scopes NFT tracing to project files when running on Vercel, and optionally expose it as a config option
• @vercel/nft: Avoid treating string constants in Object.freeze/Object.defineProperty namespace wrappers as file references, since these are Rollup/Vite module namespace artifacts, not actual filesystem dependencies