Well I think I'd say return 0; always because it's kinda successful as in there is no reason why-not that package.

As for this:

I just did what you told me in #12227 (comment) - don't really have an overview ;-)

Ok but did you try to run the code tho? Does it work and make sense to you? :) Also would need to try the why command to make sure it doesn't bork.

Ok but did you try to run the code tho?

Ahem, no ;-) You don't have a CONTRIBUTE.md - how can I build it locally?

We do but it's in the .github dir https://github.com/composer/composer/blob/main/.github/CONTRIBUTING.md

Wouldn't it be better to move CONTRIBUTING.md to the top directory?

The code looks good -here's what I did:

$ git clone -b patch-1 https://github.com/ThomasLandauer/composer
$ cd composer && php ../composer.phar install
$ bin/composer why-not composer/ca-bundle 1.5.3
# Font in orange color:
Package "composer/ca-bundle" 1.5.3 is already installed! To find out why, run `composer why composer/ca-bundle`
$ bin/composer why composer/ca-bundle
composer/composer 2.8.x-dev requires composer/ca-bundle (^1.5)

I modified the caseWhyNotProvider named 'there is no installed package depending on the package in versions not matching a specific version' (i.e. didn't create a new one). Is that OK?

Alright thanks