Docker Error Explained: unable to prepare context: unable to evaluate symlinks in Dockerfile path: GetFileAttributesEx

When building Docker images, you might run into an error like:

unable to prepare context: unable to evaluate symlinks in Dockerfile path: GetFileAttributesEx ...: The system cannot find the file specified.

This error can be confusing, especially for new Docker users. In this blog, we’ll break down what this error means, why it happens, and how to fix it effectively.

Table of Contents

❓ What Does the Error Mean?

This error typically occurs when you run the docker build command and Docker can’t locate your Dockerfile. Specifically, it’s failing to resolve the file path due to:

A missing Dockerfile
A misreferenced or incorrect path
Issues with symbolic links
Windows file system quirks

🧠 Breakdown of the Error Message

Example full error:

unable to prepare context: unable to evaluate symlinks in Dockerfile path: GetFileAttributesEx C:\path\to\Dockerfile: The system cannot find the file specified.

Here’s what it means:

“unable to prepare context”: Docker couldn’t prepare the build context (i.e., the files it sends to the Docker daemon).
“unable to evaluate symlinks in Dockerfile path”: It tried to resolve the Dockerfile path (following symlinks if any), but failed.
“GetFileAttributesEx”: A Windows system call failed—typically because the file doesn’t exist.

🛠️ Common Causes & Fixes

1. ❌ Dockerfile Doesn’t Exist

Cause: You are in the wrong directory or the Dockerfile is missing.

Fix:
Make sure the Dockerfile exists in your current directory:

ls Dockerfile   # On Linux/macOS
dir Dockerfile  # On Windows

If not, navigate to the correct folder or specify the path:

docker build -f path/to/Dockerfile .

2. ❌ Incorrect Path to Dockerfile

Cause: You may have provided a wrong or misspelled -f path.

Fix:
Ensure the path is correct and relative to your terminal’s current directory:

docker build -f ./Dockerfile .

Avoid backslashes (\) on Windows. Use forward slashes (/) or quotes:

docker build -f ".\Dockerfile" .    # Correct

3. ⚠️ Symbolic Link Issues (Especially on Windows)

Cause: Docker is unable to follow a symbolic link due to Windows filesystem limitations or permission issues.

Fix:

Avoid symlinks in your Dockerfile path.
Copy or move the actual Dockerfile to the build context directory.
Run the terminal as Administrator if required.

4. ❌ File Permissions or Path Issues

Cause: The file path is too long or inaccessible due to file system rules (common on older versions of Windows).

Fix:

Ensure you are not exceeding Windows path length limits.
Try placing the Dockerfile and context closer to the root (e.g., C:\docker\).
Check for permission issues on the file or folder.

✅ Best Practices

Always double-check the current working directory before running docker build.
Use relative paths and forward slashes when working in Windows CMD or PowerShell.
Use -f only if your Dockerfile is not named Dockerfile or is in a different location.

🔁 Example Correct Command

If you’re in the same directory as your Dockerfile:

docker build -t my-image .

If your Dockerfile is in a different location:

docker build -f ./docker/prod/Dockerfile -t my-image .

Conclusion

The unable to evaluate symlinks in Dockerfile path error usually stems from a missing or incorrectly referenced Dockerfile. By understanding how Docker builds context and resolves file paths—especially on Windows—you can avoid this issue and streamline your image builds.

Keeping your Dockerfile structure simple and your paths clean helps ensure a smooth development experience across platforms.