$ cat foo.pp
$a = $b
$b = 0
notice($a)


$ puppet apply foo.pp
cat foo.pp
Warning: Unknown variable: 'b'. (file: /Users/richardc/src/misc-puppet/foo.pp, line: 1, column: 6)
Notice: Scope(Class[main]):
Notice: Compiled catalog for penge.local in environment production in 0.03 seconds
Notice: Applied catalog in 0.01 seconds