Topic on Talk:Stable interface policy

"Long Term Support" means WMF provides bug fixes and security fixes for two years. It provides no guarantees about backwards compatibility, and it never was intended to do that.

The policy of "removing deprecated code after 1 major release (or 2)" has a really MAJOR problem. It has to do with extensions. With extensions that are not used by MediaWiki (and maybe not used by a lot of people), the extensions may only get updated during LTS revisions. When every single major release that is not a LTS release can have breaking deprecated code, when a programmer comes along and tries to bring old extensions up to date (usable with the new LTS), there is no central "checklist" (or anything) indicating what exactly has changed. Even a list would be helpful. Then at least somebody can create a utility (maintenance file) that can be run against an extension to determine what things need to be updated to be compliant with the new LTS. Specifically, I am talking about third party extensions that run in 1.31, but do not run in 1.36 (for a variety of reasons). Some of which just kind of scrapped by when going from 1.29 (or less) to 1.31.

The whole point of a LTS is so that a company (or third party extension developer) does not need to worry about all of the little changes that happen between LTS version and can just focus on the LTS versions. But it does not seem as though the development team at MediaWiki is paying attention at all to people trying to move from 1.31 LTS to 1.36 LTS.

There needs to be a maintenance function that can at least point out to a third party developer which functions calls (or hooks) are deprecated. Something like "extensionLintChecker.php" and "skinLintChecker.php" for skins. Something that will produce a report saying "File:myextension.php" is using "Deprecated function "nogo()". Replaced by "yesnow1() and againnow()" (or something to point the developer in the right direction to fixing the extension.

It's probably not what you're looking for, but each version's release notes includes a list of deprecated (and removed) code features.

Also most extensions are checked via https://codesearch.wmcloud.org/search/ in general, so this can only rly happen to extensions that have not been added to that. That service is managed https://gerrit.wikimedia.org/g/labs/codesearch and you can also file a phabricator ticket to get extensions added to it.

"LTS" is a commitment about MediaWiki itself, including the skins and extensions shipped in the "tarball". It's not a general commitment for all Wikimedia-authored extensions, and certainly not by the hundreds of independent extension authors.

If you're using an extension that doesn't bother to keep current with MediaWiki except for LTSes, I'd very strongly counsel you to stop using it and find an alternative.

"Long Term Support" means WMF provides bug fixes and security fixes for two years. It provides no guarantees about backwards compatibility, and it never was intended to do that.

Extension developers who choose to only update their extension for LTS releases may see their extension not working with intermediate releases. If that was not the case, we couldn't make any "major" releases between LTS releases. The very definition of a major release is that it breaks backwards compatibility - otherwise, it would be a minor release.