#298 Improve the error message when the image is not found in the image cache Pull request opened by pingsutw This pull request improves error handling and user guidance when working with environment image caches in Flyte, making it easier to diagnose and resolve missing environment issues. The main focus is on providing clearer error messages and removing unnecessary code. Error handling and user guidance improvements: • Replaced a warning and fallback logic with a raised

RuntimeUserError

in

_get_urun_container

, providing a detailed message and actionable steps for users when an environment is missing from the image cache. Code cleanup: • Removed an unused variable assignment (

env = deployment.envs[env_name]

) from the

_build_images

function in

src/flyte/_deploy.py

. Before: [Screenshot 2025-10-24 at 12 21 08 PM](https://private-user-images.githubusercontent.com/37936015/505471989-20b040f0-8b8b-4d95-b8ed-1c3d08735f34.png?jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.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.HkxHCxYejb0GMyulxgdEkjJ5EcpqHvhwOBTOenzmgug) After: [Screenshot 2025-10-24 at 12 27 10 PM](https://private-user-images.githubusercontent.com/37936015/505475191-9dcdbad7-f936-4ccb-b9cf-61dfff7d9f7f.png?jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.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.uzINo9XwT1ZJ6tpa2vRgVHE0OuC4XTGQfUyZsEhbF9U) flyteorg/flyte-sdk