After T148628, I tried to install Postgres via the web-installer using https://github.com/wikimedia/mediawiki/commit/31a3a94d20e2cd549c148019aa52af978d312623 with the following results:
Setting up database... done Checking for language PL/pgSQL... done Creating schema... done Creating tables... done Populating default interwiki table... done Committing changes... done Initializing statistics... done Generating secret keys... done Prevent running unneeded updates... done Creating administrator user account... done Creating main page with default content... done
Notice: Uncommitted DB writes (transaction from FOR SAVEPOINT). in ...\mw-core-pg\includes\libs\rdbms\database\Database.php on line 3460
Notice: DB transaction writes or callbacks still pending (Installer::populateSiteStats, Database::sourceFile( ...\mw-core-pg/maintenance/postgres/update-keys.sql ), Database::sourceFile( ...\mw-core-pg/maintenance/postgres/update-keys.sql ), Database::sourceFile( ...\mw-core-pg/maintenance/postgres/update-keys.sql ), Database::sourceFile( ...\mw-core-pg/maintenance/postgres/update-keys.sql ), Database::sourceFile( ...\mw-core-pg/maintenance/postgres/update-keys.sql ), Database::sourceFile( ...\mw-core-pg/maintenance/postgres/update-keys.sql ), Database::sourceFile( ...\mw-core-pg/maintenance/postgres/update-keys.sql ), User::addToDatabase, MediaWiki\Auth\TemporaryPasswordPrimaryAuthenticationProvider::providerChangeAuthenticationData, MediaWiki\Auth\LocalPasswordPrimaryAuthenticationProvider::providerChangeAuthenticationData, BotPassword::invalidateAllPasswordsForCentralId, User::saveSettings, User::addGroup, User::addGroup, User::sav in ...\mw-core-pg\includes\libs\rdbms\database\Database.php on line 3466
Fatal error: Uncaught exception 'RuntimeException' with message 'Transaction callbacks still pending.' in ...\mw-core-pg\includes\libs\rdbms\database\Database.php:714 Stack trace: #0 ...\mw-core-pg\includes\libs\rdbms\loadbalancer\LoadBalancer.php(969): Database->close() #1 [internal function]: LoadBalancer->{closure}(Object(DatabasePostgres)) #2 ...\mw-core-pg\includes\libs\rdbms\loadbalancer\LoadBalancer.php(1370): call_user_func_array(Object(Closure), Array) #3 ...\mw-core-pg\includes\libs\rdbms\loadbalancer\LoadBalancer.php(970): LoadBalancer->forEachOpenConnection(Object(Closure)) #4 ...\mw-core-pg\includes\libs\rdbms\loadbalancer\LoadBalancer.php(961): LoadBalancer->closeAll() #5 ...\mw-core-pg\includes\libs\rdbms\loadbalancer\LoadBalancer.php(1544): LoadBalancer->disable() #6 [internal function]: LoadBalancer->__destruct() #7 {main} thrown in ...\mw-core-pg\includes\libs\rdbms\database\Database.php on line 714