Why does puppet check for some packages every time I run it?

Question

Every time I run puppet on my ubuntu server, I get this:

notice: /Stage[main]/MyCompany::Role::MyApp/Package[ncurses-dev]/ensure: ensure changed 'purged' to 'present'

Every. Single. Time. Why does it do this for this particular package, and not for others, that appear in the same code block?

Package { ensure => present }
package {
    [
    "openjdk-6-jre-headless", # for SOLR
    "ncurses-dev",  # for varnishstat built from buildout, used by munin
    "pkg-config",
    "nfs-common",
    "gettext", # for building PO @deployment
    "libpcre3", "libpcre3-dev", # for varnish build / to be removed
    "libevent-dev", # for beantalk buid / to be removed
    "ffmpeg", # for thumbnails
    "gpac", # contains MP4Box, for making mp4 pseudo-streamables
    ]:;
  }

EDIT: running puppet in verbose/debug mode show this:

debug: Puppet::Type::Package::ProviderApt: Executing '/usr/bin/dpkg-query -W --showformat ${Status} ${Package} ${Version}\n ncurses-dev'

debug: Puppet::Type::Package::ProviderApt: Executing '/usr/bin/apt-get -q -y -o DPkg::Options::=--force-confold install ncurses-dev'

Executing the first command gives this:

n[DEMO]root@ucdb:~#

notice the n before the prompt

Let's admit this is a formatting problem of the debug option, here is what I get when running it with some fixes:

/usr/bin/dpkg-query -W --showformat='${Status} ${Package} ${Version}\n' ncurses-dev

unknown ok not-installed ncurses-dev

Here is what I get when running aptitude search ncurses-dev:

v ncurses-dev

The package is virtual...

Answer 1

The error appears because ncurses-dev is a virtual package.

 # apt-cache show ncurses-dev
N: Can't select versions from package 'ncurses-dev' as it is purely virtual
N: No packages found

You either want one of this two instead:

libncurses5-dev - developer's libraries for ncurses
libncursesw5-dev - developer's libraries for ncursesw

To know which one you're using, you may do this:

apt-cache showpkg ncurses-dev | sed '/Reverse Provides/,$!d'
Reverse Provides: 
libncurses5-dev 5.9-4