the 'module_working_dir' config option is used for several other parts as well.

```
[richard@devel001 puppet]$ grep -ri module_working_dir *
lib/puppet/module_tool/applications/installer.rb:      # release package in the `Puppet.settings[:module_working_dir]`.
lib/puppet/module_tool/skeleton.rb:      Pathname(Puppet.settings[:module_working_dir]) + 'skeleton'
lib/puppet/forge/cache.rb:      Pathname(Puppet.settings[:module_working_dir]) + 'cache'
lib/puppet/forge.rb:  # into the `Puppet.settings[:module_working_dir]`. Do not unpack it, just
```

This is why i decided for an other variable.