yet another attempt at stopping the core dumps

etc/security/limits.d/disable-core-dumps.conf

 # Disable core dumps since php-fpm's
 # setting doesn't seem to be enough
-*    hard   core   0
-*    soft   core   0
+*               soft    core            0
+*               hard    core            0

usr/local/bin/docker-php-entrypoint-custom

@@ -16,4 +16,5 @@ else
 fi
 
 # Launch the actual entrypoint script for this container
+ulimit -c 0
 . /usr/local/bin/docker-php-entrypoint