If you use Composer to manage dependencies on your WordPress site, you probably know the name John P. Bloch. He maintains a regularly-updated fork of WordPress that’s tailored for use with Composer. It turns up a lot in WordPress boilerplate.

Recently he made some changes to his fork, moving some of the core WordPress components to a separate repository named (appropriately) wordpress-core.

This isn’t a problem if you’re setting up a new project, as when you run composer install it will install the now three repositories (johnpbloch/wordpress, johnpbloch/wordpress-core-installer, and now johnpbloch/wordpress-core) in vendor/johnpbloch.

If you’re reading this page, you tried running composer update on an existing project and received this error message:

[InvalidArgumentException]
Two packages cannot share the same directory!

The solution is pretty simple, if a little dramatic: Use Composer to remove then reinstall WordPress.

I say “dramatic” because for that brief period after you’ve finished removing WordPress and before you’ve finished reinstalling it, your site will be a whole lot of nothing, so move with a purpose.

1. Find the line in your composer.json file that calls for WordPress. Depending on what—if any—version you’re requiring, it should look something like this:


   "johnpbloch/wordpress": "4.7.3"

   Once you find it, delete it and save your composer.json.

2. Run composer update. Composer will remove johnpbloch/wordpress and johnpbloch/wordpress-core-installer.
3. Add the line back to your composer.json and save, then run composer update again. Composer will install the three repositories.

And that should be it.