Fixing the Dyld: Library Not Loaded Error for Libicui18n.64.dylib in MacOS – A Comprehensive Guide


If you're a macOS developer, you might encounter the "dyld: Library not loaded" error related to `libicui18n.64.dylib`. This error can be frustrating, but don't worry! In this guide, we'll walk you through the steps to fix the issue and get your development environment back up and running.

## Table of Contents

- [Understanding the Error](#understanding-the-error)
- [Prerequisites](#prerequisites)
- [Solution 1: Reinstalling ICU Libraries](#solution-1-reinstalling-icu-libraries)
- [Solution 2: Setting DYLD Environment Variables](#solution-2-setting-dyld-environment-variables)
- [FAQ](#faq)
- [Conclusion](#conclusion)

## Understanding the Error

The error message looks like this:

dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.64.dylib
Referenced from: /path/to/your/executable
Reason: image not found

This error occurs when your application tries to load the ICU (International Components for Unicode) library but fails to find it in the expected location.

## Prerequisites

Before diving into the solutions, make sure you have the following installed:

- [Homebrew]( package manager
- Xcode Command Line Tools: Install by running `xcode-select --install` in the terminal

## Solution 1: Reinstalling ICU Libraries

One possible reason for this error is that the ICU libraries are missing or outdated. You can reinstall them using Homebrew:

1. Open the terminal and run the following command:

brew update && brew upgrade

2. Next, reinstall the ICU libraries:

brew reinstall icu4c

3. Verify the installation:

brew info icu4c

After the installation is complete, try running your application again. If the error persists, proceed to Solution 2.

## Solution 2: Setting DYLD Environment Variables

Another possible reason for this error is that your application's dynamic linker is unable to locate the ICU libraries. You can fix this by setting the `DYLD_LIBRARY_PATH` environment variable:

1. Open the terminal and run the following command to set the `DYLD_LIBRARY_PATH` variable:

export DYLD_LIBRARY_PATH="/usr/local/opt/icu4c/lib:$DYLD_LIBRARY_PATH"

2. Next, add the above line to your shell configuration file (`.bashrc`, `.zshrc`, or `.bash_profile`), depending on your shell:

echo 'export DYLD_LIBRARY_PATH="/usr/local/opt/icu4c/lib:$DYLD_LIBRARY_PATH"' >> ~/.bash_profile

3. Restart the terminal and try running your application again.

## FAQ

### How do I check which shell I'm using?

Run the following command in the terminal:

echo $SHELL

### Can I install the ICU libraries without Homebrew?

Yes, you can download the ICU libraries from the [official website]( and install them manually.

### What are the ICU libraries used for?

ICU libraries provide robust and full-featured Unicode and internationalization support for applications.

### Can I use a different version of the ICU libraries?

Yes, you can install a specific version using Homebrew, but make sure your application is compatible with that version.

### Can I set the DYLD_LIBRARY_PATH variable permanently?

Yes, adding the `export` line to your shell configuration file sets the variable permanently.

## Conclusion

In this guide, we covered two solutions to fix the "dyld: Library not loaded" error for `libicui18n.64.dylib` on macOS. By reinstalling the ICU libraries and setting the `DYLD_LIBRARY_PATH` environment variable, you should be able to resolve the issue and continue with your development work.

If you're looking for more tips and tricks for macOS development, check out these related articles:

- [Setting Up a Python Development Environment on macOS](
- [How to Install and Configure Git on macOS](

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