Sphinx error: Image file not readable

Did you Sphinx documentation project has failed with the error Image file not readable? This guide provides an explanation and solution to resolve the issue.

Symptom

Sphinx build failed with the errors similar to:

WARNING: image file not readable: non-existing.png
WARNING: download file not readable: path/to/non-existing.zip

Reason

Sphinx can’t find file at specified path.

Example

.. image:: non-existing.png

Or download :download:`non-existing.zip` file.

Solution

Ensure file at specified path really exist.