puppet file recurse purge filebucket

Using

  file { "/path/to/target/":
    source  => "/path/to/staging/",
    recurse => true,
    purge   => true,
  }

has one big caveat: if /path/to/target/ contains a lot of uncontrolled stuff which doesn't exist in /path/to/staging/, all this redundant stuff will be deleted and filebucketed (presumably across the network to a main file bucket running on the puppet master), and you will see this message:
info: /File[/path/to/target/bireports/DailyReport_2014-3-5.txt]: Filebucketed /path/to/target/bireports/DailyReport_2014-3-5.txt to main with sum 8f629af878d7d7fd7b70d33502100a76
notice: /File[/path/to/target/bireports/DailyReport_2014-3-5.txt]/ensure: removed

So the message is: be very careful to use "purge" if the target folder is supposed to contain plenty of other stuff. Consider moving that stuff under another folder. Or just forget the "purge".
See also:
http://docs.puppetlabs.com/references/latest/type.html#file-attribute-recurse
Incidentally in my case there were so many files that it ended up with a "Error 400 on SERVER: Could not intern from pson: regexp buffer overflow"