Gem::MissingSpecError: "Could not find 'ed25519' on Mac OS"

When running a Ruby program or script, you might encounter the error message:

Gem::MissingSpecError: Could not find 'ed25519' on Mac OS

This error occurs when a gem or library required by your program or script is missing, specifically the ed25519 gem in this case. This might happen if the gem was not installed correctly or if it’s not listed as a dependency in the program's Gemfile.

To resolve this error, you can try the following solutions:

1. Install the missing gem using gem install ed25519. This will install the gem and make it available for your program to use.

2. If you’re using Bundler to manage your gems, make sure that ed25519 is listed as a dependency in the Gemfile. Then run bundle install to install all the dependencies.

3. If you’re still encountering the same error after installing the gem, try updating your Ruby version or the Bundler gem. This might resolve any compatibility issues with the gem.

In summary, the Gem::MissingSpecError occurs when a required gem is missing from your Ruby program or script. To resolve this error, you need to install the missing gem or add it as a dependency in your Gemfile.