Unable to install theme with composer

Question

I'm trying to install Alpaca theme following the documentation.

I've created my composer.json file under app/design/frontend/ben/gotheme/composer.json

{
 "name": "ben/gotheme",
 "description": "",
 "type": "magento2-theme",
 "require": {
 "snowdog/theme-frontend-alpaca": "2.19.*",
 "ben/gotheme-front-tools": "*"
 },
 "autoload": {
 "files": [
 "registration.php"
 ]
 }
}

My registration.php looks like this:

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
use \Magento\Framework\Component\ComponentRegistrar;
ComponentRegistrar::register(
 ComponentRegistrar::THEME,
 'frontend/ben/gotheme',
 __DIR__);

When I try to install the theme running the following command from mangeto root I get an error:

composer require ben/gotheme

The error:

[InvalidArgumentException] 
Could not find a matching version of package ben/gotheme. Check the package spelling, your 
version constraint and that the package is available in a stabili ty which matches your minimum-stability (stable). 

I'm unsure what's going here. Why is composer not finding my package? Is there something I'm missing?

• jiheison: Have you configured your main composer.json to know where to look for your custom package (i.e. probably as a "path" or "artifact")? getcomposer.org/doc/05-repositories.md#hosting-your-own
• DeveloperJamie: No I have not done this. So I add the path to the theme root as a repository? I'm using paths in this case.
• jiheison: I believe that you would want to configure your main composer.json by running something like: "composer config repositories.ben path app/design/frontend/ben/gotheme". This should add the relevant path repository to your main composer.json, and allow it to be found when you run "composer require".
• DeveloperJamie: I ended up adding it manually in the composer.json and running composer update. But, I see it would have been easier to just run composer require. Thank you. If you can make that into an answer I will accept.
• jiheison: I'm glad that it is working.

Answer 1

I have a pretty narrow understanding of composer, so perhaps someone will add a more comprehensive response.

The issue is that the main composer.json must be configured to look for any custom package that is not hosted in the default packagist.org repository (https://getcomposer.org/doc/05-repositories.md#hosting-your-own)

This can be done by using, e.g. composer config repositories.ben path app/design/frontend/ben/gotheme

In this example "repositories.ben" sets "ben" as the repository name. The path should be the path to the directory where your package's composer.json is located. (This could also be a path to a custom module in /vendor).

Running this command will add a repository configuration to the main composer.json, such as in the following example, where it is added to the existing Magento2 repository configuration:

"repositories": {
 "0": {
 "type": "composer",
 "url": "https://repo.magento.com/"
 },
 "ben": {
 "type": "path",
 "url": "app/design/frontend/ben/gotheme"
 }
},

(It is also fine to edit composer.json directly)

Once the repository is configured, the package will be found when running, e.g. composer require ben/gotheme