MediaWiki 1.32/wmf.15 updated API query modules for MCR.
See rMWfb1b454e6a6f: Merge "API: Update query modules for MCR" / T200568: Make API query modules aware of MCR:
- action=query&prop=revisions now takes a 'rvslots' parameter to indicate the multi-content revision slots for which content should be returned. It also has a new rvprop, 'roles', to indicate which roles have slots. A deprecation warning will be issued if rvprop=content or rvprop=contentmodel are used without rvslots.
- The rvcontentformat parameter to action=query&prop=revisions has been deprecated. Clients should be prepared to deal with the default format for relevant models.
- Use of the deprecated parameters rvexpandtemplates, rvgeneratexml, rvparse, rvdiffto, rvdifftotext, rvdifftotextpst, rvcontentformat, or the deprecated rvprop=parsetree is forbidden with the new 'rvslots' parameter.
- action=query&prop=deletedrevisions, action=query&list=allrevisions, and action=query&list=alldeletedrevisions are changed similarly to &prop=revisions (see the three previous items).
Today the below started appearing in my logs for Commons.
2018-08-02 01:04:36 api.py, 1900 in _handle_warnings: WARNING API warning (main): Subscribe to the mediawiki-api-announce mailing list at <https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce> for notice of API deprecations and breaking changes. Use [[Special:ApiFeatureUsage]] to see usage of deprecated features by your application. 2018-08-02 01:04:36 api.py, 1900 in _handle_warnings: WARNING API warning (revisions): Because "rvslots" was not specified, a legacy format has been used for the output. This format is deprecated, and in the future the new format will always be used.