Comment 0 for bug 1506066

The use of the 'pick' function to look up variables from other classes can throw scope-related warnings on nodes that don't have all of those classes included, as 'pick' attempts to qualify all variables passed before selecting the first defined value. For example:

Nodes that have the nova::compute class included and on which we want to enable the VNC service (the default), i.e a compute node, get nova::vncproxy::common included automatically, but we don't include nova::vncproxy so we see the following error:

Warning: Scope(Class[Nova::Vncproxy::Common]): Could not look up qualified variable '::nova::vncproxy::host'; class ::nova::vncproxy has not been evaluated

The reverse is true on a control node where we do have nova::vncproxy included but not nova::compute:

Warning: Scope(Class[Nova::Vncproxy::Common]): Could not look up qualified variable '::nova::compute::vncproxy_host'; class ::nova::compute has not been evaluated