Steps to replicate the issue (include links if applicable):

• Use the query service (for Wikidata or a third-party install) querying for constraint violations, for example:

SELECT ?s ?y WHERE {
  ?s wikibase:hasViolationForConstraint ?y.
} LIMIT 10

What happens?:

• Nothing appears.

What should have happened instead?:

• Either (1) property constraint violations should appear or (2) there should be an error raised if the query is not possible or is deprecated. If the latter, this should be indicated in documentation.

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):

• For Wikidata:

MediaWiki 1.43.0-wmf.11 (7df99f2)
20:36, 24 June 2024
PHP 7.4.33 (fpm-fcgi)
ICU 67.1
MariaDB 10.6.17-MariaDB-log
wikidiff2 1.14.1
Pygments 2.17.2
LilyPond 2.22.0
Elasticsearch 7.10.2
LuaSandbox 4.1.2
Lua 5.1.5

Other information (browser name/version, screenshots, etc.):

If deprecated, there really should be some way to reproduce this functionality. For smaller wikis (even those locally hosted), this is a really useful feature to have to take stock of violations. Individual constraint reports can take ages to go through, and an auto-generated full list is much more convenient.

See also: T201147: Expose constraint violations to WDQS using event queue