Steps to reproduce:
- install MediaWiki-Vagrant with some extension role enabled
- break the extension's extension.json file
- run some maintenance script
There will be an error like this on stdout:which will be logged absolutely nowhere (which is problematic when the maintenance script is is run by some background process or in any other way where stdout is not visible to the user).
On one hand, it's a good thing that extensions can modify error handling (actually they can't, see T153256; but it makes sense to allow extension registration first, to handle that use case). On the other hand, there should be *some* error handling in the early steps of startup.