# Py\_executable in runtime\_env ignored when starting Ray actor (ModuleNotFoundError)

**URL:** https://discuss.ray.io/t/py-executable-in-runtime-env-ignored-when-starting-ray-actor-modulenotfounderror/22989
**Category:** Ray Core
**Created:** [August 11, 2025, 3:41pm UTC](https://discuss.ray.io/t/py-executable-in-runtime-env-ignored-when-starting-ray-actor-modulenotfounderror/22989 "2025-08-11T15:41:03Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![raphael](https://avatars.discourse-cdn.com/v4/letter/r/edb3f5/32.png) [@raphael](https://discuss.ray.io/u/raphael)
#### Post date: [August 11, 2025, 3:41pm UTC](https://discuss.ray.io/t/py-executable-in-runtime-env-ignored-when-starting-ray-actor-modulenotfounderror/22989/1 "2025-08-11T15:41:03Z")

</div>

**Severity:** High - Completely blocks me

**Environment:**

- **Ray version:** 2.48.0

- **Python version:** 3.12.11

- **OS:** Ubuntu 22.04, no Docker

- **Infra:** Ray autoscaler with AWS EC2

* * *

### What I expected

I have a Ray actor defined in a package `app_commons`. When I try to instantiate it remotely with `py_executable`, it fails with:

```auto
ModuleNotFoundError: No module named 'app_commons'

```

Here’s the code:

```auto
from app_commons.features.queue_actor import QueueActor

actor = QueueActor.options(
    runtime_env={
        "py_executable": "uv run --with app-commons==0.1.10 --",
    },
    name=f"{feature}_queue_actor",
    num_cpus=0.1,
).remote(feature)

```

However, I launch other things in my cluster **the exact same way** in Ray Serve, and they work fine.

For example:

```auto
- name: ai_ocr_service
  route_prefix: /ai_ocr_service
  import_path: micro_services.ocr_service:app
  runtime_env:
    {
      "py_executable": "uv run --with micro-services==0.0.20 --with ai-ocr==1.3.9 --",
    }
  deployments:
    - name: OCRService
      max_ongoing_requests: 10
      autoscaling_config:
        target_ongoing_requests: 1

```

This works without any dependency issues.

* * *

### My expectation

The actor should start without dependency issues because I am explicitly installing the dependency (package `app-commons` which provides the `app_commons` module). I almost feel like the `py_executable` I pass to the actor is ignored entirely, because I can replace it with `lkjlkjio` and the only error I get is still the `ModuleNotFoundError` — no additional error about an invalid command.

**Question:** Is `py_executable` in `runtime_env` actually supported for Ray actors the same way it is for Ray Serve YAML deployments? If not, what is the correct way to dynamically install dependencies for a Python package when creating an actor?

_Thank you_

---

<div class="post-metadata">

### Author: ![eoakes](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/eoakes/32/7825_2.png) [@eoakes](https://discuss.ray.io/u/eoakes)
#### Post date: [September 24, 2025, 4:44pm UTC](https://discuss.ray.io/t/py-executable-in-runtime-env-ignored-when-starting-ray-actor-modulenotfounderror/22989/2 "2025-09-24T16:44:57Z")

</div>

@raphael if this is still a problem could you please file a github issue on the Ray repo with a reproduction script?