[Conda] Error: CondaFileNotFoundError — environment.yml not found — How to Fix It

Summary

The CondaFileNotFoundError: environment.yml not found error occurs when Conda cannot locate the environment definition file specified in your command. This usually happens if you’re running the command from the wrong directory, the file name is incorrect (e.g., environment.yaml instead of environment.yml), or the file simply doesn’t exist. Ensure the file path and name are correct, or specify its full location with the -f option.

Context

The environment.yml file defines all dependencies, channels, and metadata for a Conda environment. When you run conda env create -f environment.yml, Conda expects to find this file in your current working directory unless you explicitly provide another path. If the file is missing, misnamed, or inaccessible, Conda raises this error and stops execution. It’s a common issue when cloning projects from GitHub or moving between directories without verifying paths.

Probable Cause

  • The file environment.yml doesn’t exist in your current working directory.
  • You’re running the command from the wrong folder or path.
  • The file is named differently (e.g., environment.yaml or env.yml).
  • Windows is hiding extensions (e.g., the file is actually environment.yml.txt).
  • The YAML file exists but has syntax or formatting errors (bad indentation, tabs, etc.).

Quick Fix

Follow these steps to locate and use the correct environment.yml file:

  1. Verify that the file exists in your current directory.
# Windows
dir environment.yml

# Linux/macOS
ls environment.yml
  1. If not found, navigate to the correct folder:
cd path/to/your/project
conda env create -f environment.yml
  1. If the file has a different name, specify it explicitly:
conda env create -f env.yaml
  1. If the file is stored elsewhere, use its full path:
# Windows
conda env create -f C:\Users\\Downloads\environment.yml

# Linux/macOS
conda env create -f ~/Downloads/environment.yml
  1. Validate the file’s structure — it must start with name: and dependencies: keys.
name: myenv
dependencies:
  - python=3.11
  - numpy
  - pandas
  1. If the file seems invalid, regenerate it from an existing environment:
conda env export > environment.yml

Full Example

A user runs: 

conda env create -f environment.yml

and gets: 

CondaFileNotFoundError: environment.yml not found

They check their current directory: 

ls
main.py  README.md  data/

The file isn’t present. They navigate to the correct folder where it exists: 

cd ~/Projects/MyApp
ls
environment.yml  requirements.txt
conda env create -f environment.yml

The environment creation completes successfully, confirming the issue was just an incorrect path.

Pitfalls & Debug

  • Symptom: File exists but Conda still fails → Fix: Check for hidden extensions (e.g., .yml.txt).
  • Symptom: “Invalid YAML” error → Fix: Ensure indentation uses spaces, not tabs.
  • Symptom: Wrong filename → Fix: Rename to environment.yml or specify -f <name>.
  • Symptom: Using relative paths incorrectly → Fix: Use absolute paths starting with / or C:\.
  • Symptom: Command run in IDE terminal → Fix: Confirm your IDE’s working directory matches the project root.

Validation & Next Steps

After resolving the issue, confirm that the environment was created: 

conda env list

Your new environment should appear in the list. To export it later, run: 

conda env export > environment.yml

This ensures a valid YAML file is always available for future recreation.

Sources

Anaconda Documentation — Managing Conda environments
Stack Overflow — “environment.yml not found” troubleshooting threads
conda-forge Community — environment file best practices
YAML.org — syntax and formatting reference

Labels: Tool/Conda, OS/Windows-macOS-Linux, Topic/File-Environment