I needed to enhance composer.local.json:
composer.local.json
{ "require": { "mediawiki/semantic-media-wiki": "~3.2" }, "extra": { "merge-plugin": { "include": [ "extensions/OATHAuth/composer.json" ] } } }
Without the extra section I broke the OATHAuth extension (bundled with MW 1.31+).
extra
Webracer999 (talk)