v6.9.0+ broken build on cloudflare workers with nuxt/nitro. Uncaught TypeError: Zv.hasOwnProperty is not a function

[serhii-chernenko]

Describe the Bug

I was upgrading my project deps and found deploy issue on cloudflare workers caused of one of deps. I started While upgrading my project dependencies, I encountered a deployment issue on Cloudflare Workers caused by one of the dependencies. I took a step-by-step approach to identify the problem and found that the resend package was the culprit. When I upgraded resend from version 6.4.2 to the latest 6.9.1, I received an error during deployment and preview using wrangler.

The project is based on Nuxt (and Nitro).

[wrangler:info] ✨ Parsed 5 valid header rules.
✘ [ERROR] service core:user:besidka-preview: Uncaught TypeError: Zv.hasOwnProperty is not a function

    at null.<anonymous> (index.js:71960:23) in .output/server/chunks/nitro/nitro.mjs
    at null.<anonymous> (index.js:11:59) in __init
    at null.<anonymous> (index.js:91503:1)

✘ [ERROR] The Workers runtime failed to start. There is likely additional logging output above.

Nuxt info:

|                      |                                                                                                                                                                                                                                    |
| -------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Operating system** | `macOS 25.2.0`                                                                                                                                                                                                                     |
| **CPU**              | `Apple M1 Pro (10 cores)`                                                                                                                                                                                                          |
| **Node.js version**  | `v24.8.0`                                                                                                                                                                                                                          |
| **nuxt/cli version** | `3.32.0`                                                                                                                                                                                                                           |
| **Package manager**  | `pnpm@10.28.2`                                                                                                                                                                                                                     |
| **Nuxt version**     | `4.2.1`                                                                                                                                                                                                                            |
| **Nitro version**    | `2.13.1`                                                                                                                                                                                                                           |
| **Builder**          | `vite@7.3.1`                                                                                                                                                                                                                       |
| **Config**           | `$development`, `app`, `colorMode`, `compatibilityDate`, `css`, `devtools`, `eslint`, `experimental`, `features`, `fonts`, `future`, `icon`, `mdc`, `modules`, `nitro`, `pwa`, `runtimeConfig`, `svgo`, `typescript`, `vite`       |
| **Modules**          | `@nuxt/eslint@1.13.0`, `@nuxt/fonts@0.12.1`, `@nuxt/icon@2.2.1`, `@nuxt/image@2.0.0`, `@nuxtjs/color-mode@3.5.2`, `@nuxtjs/device@3.2.4`, `@nuxtjs/mdc@0.18.4`, `nuxt-svgo@4.2.6`, `@vueuse/nuxt@14.2.0`, `@vite-pwa/nuxt@1.1.0`   |

Screenshot of error on 6.9.1:

NOTE

I found that it still works on 6.8.0. So, it breaks the deploy from 6.9.0

Link to the code that reproduces this issue

https://github.com/besidka/besidka

To Reproduce

Follow this steps:
https://github.com/besidka/besidka?tab=readme-ov-file#steps

The last step is

pnpm run preview # not dev

Expected Behavior

Screenshot of success preview on 6.4.2:

What's your node version? (if relevant)

No response

[StVladyslav]

I have the same issue.
Resend version: 6.9.1
Nuxt version: 4.3.1
Wrangler version: 4.63.0

[gabrielmfern]

Please provide a minimal reproduction, a reproduction as big as this takes our available time from looking at other issues, so I'm going to close this as not planned until we have a minimal reproduction.

[serhii-chernenko]

@gabrielmfern wdym it's not provided? It IS literally in the issue description:

👉 👉👉 ‼️ STEPS TO REPRODUCE ‼️ 👈👈👈

Clone the repository.

git clone git@github.com:besidka/besidka.git

Go to the project directory. Install the dependencies.

cd besidka
pnpm update resend --latest

Copy ENV related files.

cp .dev.vars.example .dev.vars

Generate environment types for the project.

pnpm run cf-typegen

Prepare drizzle migrations.

# Expected output is .drizzle/migrations/*.sql
pnpm run db:generate

Apply the migrations to the D1 database.

# Expected output is .wrangler/state/v3/d1/*.sqlite
pnpx wrangler d1 migrations apply DB

Start Cloudflare Workers preview server

pnpm run preview

ERROR

Downgrade to 6.8.0 (last working version)

pnpm add resend@6.8.0

Start Cloudflare Workers preview server again

pnpm run preview

No error

[gabrielmfern]

As I said, the reproduction is an entire project, it isn't minimal, it takes more time to reproduce, and isn't sustainable, if you, or someone else, do provide something more minimal we'll reopen and look into it.

[serhii-chernenko]

@gabrielmfern here's the minimal reproduction based on Nitro v3 + Vite + Cloudflare Workers + Resend:
https://github.com/serhii-chernenko/nitro-cloudflare-resend-issue

[gabrielmfern]

Thank you! This really helps, and this way we can get to your issue quicker :)

[gabrielmfern]

Seems like this was fixed in v6.9.2 through #820; the reproduction no longer breaks in it too. Going to close; if anyone still experiences this, let me know and I'll reopen.