It's should be trivial to use non packaged composer, though. You can grab a phar from their website...

I'd suspect most people are using composer 2 anyway these days, but this would mean some potential breakages

Commit b1b2849 fixed it, thanks.

We're catching this error when running MW 1.35.2 and the rebuildLocalisationCache.php script.

This option is still needed for Mobile FrontEnd.

In T196816#4270680, @matmarex wrote:

If you configure your PHP/server to display error messages (https://www.mediawiki.org/wiki/Manual:How_to_debug#PHP_errors), you do get a message like this instead of a blank page:

In T197518#4294976, @Reedy wrote:

In T197518#4294969, @Noloader wrote:

Does anyone know if MediaWiki 1.31 works with CentOS 7 and PHP 7.1?

Why? What is that going to fix?

Does anyone know if MediaWiki 1.31 works with CentOS 7 and PHP 7.1?

In T197518#4294946, @Reedy wrote:

...
I'd suggest replacing the whole vendor folder from the tarball (delete the one in your MW dir, then copy the one out of the tarball in its place)

I don't believe I installed something called oojs. So do we delete all the oojs files? It looks like:

Thanks everyone.

Also see Issue 14304, Please provide texvc, texcheck and LaTeXml for MediaWiki math markup in the CentOS 7 issue tracker.

After thinking about this, this is a Same Origin violation in the browser. In our case these origins were different from SOP's point of view:

In T150115#2774360, @Krenair wrote:

We have ServerName wikipedia and ServerAlias *.wikipedia.org with wgServer taking the format //$lang.wikipedia.org, and I don't think I've seen this problem occur.