# Trouble deploying simple app with uv

**URL:** <https://discuss.ray.io/t/trouble-deploying-simple-app-with-uv/23003>\
**Category:** Ray Serve\
**Created:** [August 15, 2025, 2:32pm UTC](https://discuss.ray.io/t/trouble-deploying-simple-app-with-uv/23003 "2025-08-15T14:32:07Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Dominic\_Laflamme](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/dominic_laflamme/32/7394_2.png) [@Dominic\_Laflamme](https://discuss.ray.io/u/Dominic_Laflamme)\
**Post date:** [August 15, 2025, 2:32pm UTC](https://discuss.ray.io/t/trouble-deploying-simple-app-with-uv/23003/1 "2025-08-15T14:32:07Z")

</div>

I’m trying to deploy a Ray Serve app to an already running cluster (connecting with `ray.init(address="ray://<HEAD>:10001")`). The project is a package: `myapp/` (with ` __init__.py`) contains `app.py` that builds the graph (`entry = Ingress.bind(Embedder.bind(), Inferencer.bind())`), and a `deploy.py` does `serve.run(entry, name="gradio-mix")`. I ship code via `runtime_env` (`working_dir` pointing at the project root; also tried adding `py_modules: ["myapp"]`) and set up deps with either `setup_commands: ["uv sync --frozen"]` or `py_executable: "uv run"` (no flags). Logs show the working dir is uploaded (e.g., `gcs://_ray_pkg_...`) and the runtime env is created, but deployment fails when Serve unpickles the deployment on the cluster with:

```auto
File “…/ray/serve/_private/config.py”, line 703, in deployment_defself._deployment_def = cloudpickle.loads(self.serialized_deployment_def)ModuleNotFoundError: No module named ‘myapp’

```

So it looks like the Serve worker that deserializes the project can’t import the packaged module even though `myapp/ __init__.py` exists and the env reports created. Any pointers on what I’m missing to make the module visible to Serve actors in client mode? (Python 3.12; using FastAPI+Gradio ingress.)

here’s my project layout:

```auto
project-root/
├─ pyproject.toml # deps (ray[serve], fastapi, gradio)
├─ uv.lock                     
├─ deploy.py # connects to running cluster and calls serve.run(entry, name=...)
├─ pyproject.toml
└─ myapp/
   ├─ __init__.py # empty
   └─ serve_app.py # defines APP_NAME, deployments, ingress, and `entry`

```

here’s a link to a zip file containing the project

[ray\_serve\_bug.zip](https://drive.google.com/file/d/1CMSwmRJFrrAwAEfp1NajTNWfJCJ_Rx1H/view?usp=drive_link)

**1. Severity of the issue: (select one)**  
High: Completely blocks me.

**2. Environment:**

- Ray version: 2.48.0
- Python version: 3.12.9
- OS: ubuntu
- Cloud/Infrastructure: docker running on a AWS EC2 instance
- Other libs/tools (if relevant):

**3. What happened vs. what you expected:**

- Expected: cloudpickle.load finds my module
- Actual: cloudpickle.load fails to find the inlined module

---

<div class="post-metadata">

**Author:** ![Dominic\_Laflamme](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/dominic_laflamme/32/7394_2.png) [@Dominic\_Laflamme](https://discuss.ray.io/u/Dominic_Laflamme)\
**Post date:** [August 17, 2025, 2:59pm UTC](https://discuss.ray.io/t/trouble-deploying-simple-app-with-uv/23003/2 "2025-08-17T14:59:57Z")

</div>

after trying to debug this further, I’d say running a yaml-based AWS cluster with Ray 2.48.0 doesn’t actually use or support astral-uv despite what the documentation says, either that or uv support is broken in 2.48.0.