/vendor/autoload.php is provided by composer, not MediaWiki, isn't it?

In T213935#4884739, @Jdforrester-WMF wrote:

/vendor/autoload.php is provided by composer, not MediaWiki, isn't it?

Perhaps I've misinterpreted the intent of the changes made (see catus.php on Gerrit). TextCat has not been updated in CirrusSearch since the changes have been made, so we are still running the previous version in production. I may have hallucinated a "../" in the require path. Ugh. Composer and php are not my strong suites by any stretch of the imagination. As it stands, I can't run the latest version of TextCat on the command line on my laptop (which doesn't have composer installed).

The change was made without any explanation in the patch or changes to documentation, and now when you download or clone from GitHub it doesn't work out of the box if you follow the documentation.

I'll update the task description. Thanks.

Change 484727 had a related patch set uploaded (by Tjones; owner: Tjones):
[wikimedia/textcat@master] Remove Dependency on Composer from TextCat

https://gerrit.wikimedia.org/r/484727

Right now, from what I understand, textcat is a composer package, which means once checked out, it needs "composer install" to deliver all the dependencies (which are actually none in non-dev mode, but that's beside the point as all composer packages need that). This is pretty standard things for composer-based modules AFAIK and nothing unusual. However, for people that don't want to use composer ecosystem it may be non-obvious that this is what is happening. So we can:

1. Document the "composer install" step
2. Revert the composer requirement

I have slight preference for the first alternative, as composer is rather common in modern PHP world, but if it makes trouble, the second alternative is available. In any case, there's no reason to need any of the mediawiki, only composer, so if it doesn't work with composer alone it's a problem and needs to be fixed.

Change 484727 abandoned by Tjones:
Remove Dependency on Composer from TextCat

https://gerrit.wikimedia.org/r/484727