Many users will not have apc and apcu enabled on the same servers. Symfony Console's \Symfony\Component\Console\Application::find method will attempt to find commands that match partial names but this cannot work when there are commands whose namespaces are subsets of other commands.

For example, when all extensions are enabled, it's not possible to abbreviate most of the commands in either apc or apcu namespace:

$ ./bin/cachetool a:k:f some-key --no-ansi
                                                       
  Command "a:k:f" is ambiguous.                        
  Did you mean one of these?                           
      apc:key:fetch  Shows the content of an APC key   
      apcu:key:fetch Shows the content of an APCu key  
                                                       

When the config file specifies which extensions to support, calling commands with abbreviations is possible:

extensions: [opcache, apcu]

$ ./bin/cachetool a:k:f some-key
APCu key=some-key has value='thing'

To avoid breaking backward compatibility, \CacheTool\Console\Config::__construct now uses array_replace to provide defaults when config properties aren't set in the $config argument.