Nuxt Content 3.4.0 generating 'manifest-route-rule' middleware already exists warnings
Hi everyone!
I recently migrated Nuxt Content from v2 and now I'm constantly getting these warnings whenever I save a markdown file:
ℹ File work/lining-project.md changed on content collection @nuxt/content 11:43:59 AM
[11:43:59 AM] WARN 'manifest-route-rule' middleware already exists at './node_modules/nuxt/dist/app/middleware/manifest-route-rule.js'. You can set override: true to replace it.
Sometimes it still updates the generated page, sometimes it doesn't and I'm forced to restart yarn dev to make update—I never found any rhyme or reason as to why that is.
Do you have any idea what can be causing this? FWIW, here's my content.config.ts:
import { defineCollection, defineContentConfig, z } from "@nuxt/content";
export default defineContentConfig({
collections: {
content: defineCollection({
source: "**.md",
type: "page",
schema: z.object({
tags: z.array(z.string()),
preview: z.string(),
headline: z.string(),
}),
}),
},
});14 Replies
Hi @rooknoob. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave:
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The warning you're experiencing with Nuxt Content 3.4.0 about "'manifest-route-rule' middleware already exists" is a known issue related to how Nuxt handles hook unregistration during hot module replacement.
This issue occurs because when you save a markdown file, Nuxt Content triggers a reload, but the old Nuxt hooks are still responding alongside the new ones. This creates a race condition where both instances try to register the same middleware.
Why this happens
The problem stems from how Nuxt handles hooks during restarts. When a file changes and triggers a reload, the old hooks aren't properly unregistered before the new ones are added, causing duplicate registrations of middleware like 'manifest-route-rule'.
This issue was addressed in a Nuxt pull request that specifically fixes the problem by "unregistering hooks the moment
close is called" GitHub PR #27637. The PR description mentions exactly the warning you're seeing:
Solutions
1. Update Nuxt: Make sure you're using the latest version of Nuxt, as this issue has been fixed in newer releases.
2. Restart development server: As you've noticed, sometimes restarting the development server with yarn dev resolves the issue temporarily.
3. Force a clean upgrade: If you're still experiencing issues after updating, you might need to force a clean upgrade:
This command will delete your lockfile and node_modules folder to ensure you get the latest versions, as recommended for similar issues in this Stack Overflow answer.
Your content.config.ts file looks correct and is not likely the source of the problem. This is more of an internal Nuxt issue related to how it handles hot module replacement and hook registration/unregistration during development.
----------------------
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----------------------<@927767054029844540> Kapa.ai is still learning and improving, please let me know how I did by reacting below.
@kapa.ai I'm using Nuxt 3.16.1. I did force a clean upgrade just to make sure, and also tried deleting .nuxt, .output, .yarn, .data, yarn.lock. Here's my package.json:
{
"name": "nuxt-app",
"private": true,
"type": "module",
"scripts": {
"build": "nuxt build",
"dev": "nuxt dev",
"generate": "nuxt generate",
"preview": "nuxt preview",
"postinstall": "nuxt prepare"
},
"dependencies": {
"@nuxt/content": "3.4.0",
"@nuxt/fonts": "0.11.0",
"@nuxt/image": "^1.10.0",
"@nuxtjs/plausible": "^1.2.0",
"@tailwindcss/vite": "4.0.15",
"gsap": "^3.12.7",
"hls-video-element": "^1.5.0",
"media-chrome": "4.8.0",
"nuxt": "^3.16.1",
"splitting": "github:awfulcode/Splitting",
"swiper": "11.2.6",
"tailwindcss": "4.0.15",
"vue": "^3.5.13",
"vue-router": "^4.5.0",
"vue-starport": "^0.4.0"
},
"devDependencies": {
"@nuxt/devtools": "^2.3.1",
"@vueuse/core": "^13.0.0",
"@vueuse/nuxt": "^13.0.0",
"patch-package": "^8.0.0",
"prettier": "3.5.3",
"prettier-plugin-tailwindcss": "^0.6.11",
"wrangler": "4.4.0"
},
"prettier": {
"plugins": [
"prettier-plugin-tailwindcss"
]
},
"packageManager": "[email protected]+sha512.5a0afa1d4c1d844b3447ee3319633797bcd6385d9a44be07993ae52ff4facabccafb4af5dcd1c2f9a94ac113e5e9ff56f6130431905884414229e284e37bb7c9"
}
Maybe there's a compatibility issue with one of these?Let me check the knowledge base for you again. One moment! :books:
----------------------
Based on your package.json, I can see a potential compatibility issue that might be causing the 'manifest-route-rule' middleware warnings. The most likely culprit is your version of
@nuxt/content.
You're using @nuxt/content version 3.4.0 with Nuxt 3.16.1, which could be causing version compatibility issues. According to the knowledge sources, there have been several issues with dependency mismatches in Nuxt 3.16.x that can cause various problems.
The most relevant issue appears to be that you're using an older version of Nuxt Content with a newer version of Nuxt. This type of version mismatch has been documented to cause problems in several GitHub issues and Stack Overflow posts.
Recommended solution:
Update your Nuxt Content package to a newer version that's compatible with Nuxt 3.16.x:
This should bring you to a version that's compatible with your Nuxt 3.16.1 installation.
Additionally, there have been several issues reported with dependency conflicts in Nuxt 3.16.0 specifically GitHub Issue #31340 and GitHub Issue #31265 that mention problems with various modules including @nuxt/image.
If updating Nuxt Content doesn't resolve the issue, you might want to try:
1. Ensuring all your Nuxt-related packages are on their latest versions
2. Checking for conflicting versions of shared dependencies (like ohash which has been mentioned in several issues)
3. Running yarn why [package-name] to check for any dependency conflicts
The warning you're seeing is specifically related to hook registration during hot module replacement, as mentioned in the previous answer, but the root cause in your case is likely the outdated Nuxt Content version that's not fully compatible with Nuxt 3.16.1.
----------------------
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
----------------------<@927767054029844540> Kapa.ai is still learning and improving, please let me know how I did by reacting below.
@kapa.ai The warning mentions setting override: true as a possible fix. How can I do that?
Let me check the knowledge base for you again. One moment! :books:
----------------------
The warning suggests setting
override: true to replace the existing middleware. This option can be used when adding route middleware dynamically in Nuxt.
Based on the knowledge sources, you can set the override option when using the addRouteMiddleware() utility function. However, in your specific case with Nuxt Content 3.4.0, this isn't something you would directly configure yourself since the middleware is being registered by the Nuxt Content module internally.
The proper solution is to update your Nuxt Content version to match your Nuxt version (3.16.1), as I suggested previously. The version mismatch is likely causing the conflict where both versions are trying to register the same middleware.
If you want to try a workaround while keeping your current versions, you could create a plugin that explicitly adds the middleware with the override option:
This plugin would force the middleware to be overridden, potentially preventing the warning. However, this approach is not recommended as a permanent solution because:
1. It might interfere with the actual functionality of the middleware
2. It's addressing the symptom rather than the root cause (version mismatch)
3. It could lead to unexpected behavior in your application
The most reliable solution remains updating your Nuxt Content to a compatible version:
This should resolve the middleware conflict by ensuring both Nuxt and Nuxt Content are using compatible versions of the internal utilities.
----------------------
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
----------------------<@927767054029844540> Kapa.ai is still learning and improving, please let me know how I did by reacting below.
@kapa.ai Could I set it inside defineNuxtRouteMiddleware?
Let me check the knowledge base for you again. One moment! :books:
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No, you can't set the
override: true option directly inside defineNuxtRouteMiddleware. The override option is specifically for the addRouteMiddleware function, not for defineNuxtRouteMiddleware.
The defineNuxtRouteMiddleware helper is used to create middleware functions, while addRouteMiddleware is used to register those middleware functions with Nuxt, as shown in the documentation:
According to the Nuxt documentation, the override option is part of the AddRouteMiddlewareOptions interface that's passed as the second parameter to addRouteMiddleware.
If you want to override the 'manifest-route-rule' middleware, you would need to use a plugin that calls addRouteMiddleware as I suggested in my previous answer:
However, I still recommend updating your Nuxt Content version to match your Nuxt version as the proper solution to this issue.
----------------------
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
----------------------<@927767054029844540> Kapa.ai is still learning and improving, please let me know how I did by reacting below.
@kapa.ai So is that warning being generated by Nuxt Content or by Nuxt itself?
Let me check the knowledge base for you again. One moment! :books:
----------------------
Based on the knowledge sources, the warning about "'manifest-route-rule' middleware already exists" is being generated by Nuxt itself, not by Nuxt Content directly.
This warning is related to Nuxt's internal hook and middleware registration system. According to the GitHub pull request #27637, this specific warning occurs due to a race condition in Nuxt's hook system during hot module replacement:
Occasionally users may have noticed race conditions when restarting Nuxt because of a file rename/move. A warning might show up, like this:
This was because the old Nuxt hooks were still responding - so calling app:resolve was triggering adding route middleware from the old Nuxt as well as the new one.
The 'manifest-route-rule' middleware is part of Nuxt's internal routing system, specifically related to the build manifest functionality mentioned in GitHub PR #21641.
While Nuxt Content is triggering the hot module reload when you save a markdown file (which is why you see the warning after saving content), the actual warning message is coming from Nuxt core as it tries to register the same middleware twice during the reload process.
This is why updating both Nuxt and Nuxt Content to compatible versions is important - they need to work together properly with the same internal APIs and hook systems.
----------------------
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
----------------------<@927767054029844540> Kapa.ai is still learning and improving, please let me know how I did by reacting below.