When updating civicrm/civicrm-core (5.28.3 => 5.29.0), the process get frozen while
[Executed: Upgrade DB to 5.29.alpha1: Fill civicrm_relationship_cache (1 => 5000)]
After reinstallation of a backup and removal of all caches, still the update gives a same frozen installation.
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Here's what I found in the Civi logs:
465 Sep 07 20:44:40 [info] $CRM_Queue_Page_AJAX_runNext_error = PEAR_Exception: "DB Error: constraint violation"
421 Sep 07 20:44:40 [debug] $backTrace = #0 /PATH/vendor/civicrm/civicrm-core/CRM/Core/Error.php(937): CRM_Core_Error::backtrace("backTrace", TRUE)
385 Sep 07 20:44:40 [error] $Fatal Error Details = Array
383 Sep 07 20:44:39 [info] Running task: Upgrade DB to 5.29.alpha1: Fill civicrm_relationship_cache (5001 => 10000)
381 Sep 07 20:44:37 [info] Running task: Upgrade DB to 5.29.alpha1: Fill civicrm_relationship_cache (1 => 5000)
379 Sep 07 20:44:37 [info] Running task: Install eventcart extension
377 Sep 07 20:44:36 [info] Running task: Upgrade DB to 5.29.alpha1: SQL
375 Sep 07 20:44:36 [info] Running task: Upgrade DB to 5.29.alpha1
373 Sep 07 20:44:35 [info] Running task: Begin Upgrade to 5.29.alpha1
371 Sep 07 20:44:35 [info] Running task: Checking extensions
369 Sep 07 20:44:34 [info] Running task: Cleanup old files
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In Drupal's logs :
Message Warning: Declaration of CRM_Volunteer_BAO_Project::copyValues(&$params, $serializeArrays = false) should be compatible with CRM_Core_DAO::copyValues($params) in require_once() (line 36 of /PATH/web/sites/default/files/civicrm/ext/org.civicrm.volunteer/CRM/Volunteer/BAO/Project.php)