title: ubuntu 12.04 libudev-dev won't install because of dependencies
body: <p>I have a some sample c++ code that receives hotplug events using the udev library. It worked fine in Ubuntu 10.04. It's only prerequisite was the libudev-dev package:
      sudo apt-get install libudev-dev</p>
  
  <p>But when I tried to install that package in 12.04, I get:</p>
  
  <pre><code>sudo apt-get install libudev-dev
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  Some packages could not be installed. This may mean that you have
  requested an impossible situation or if you are using the unstable
  distribution that some required packages have not yet been created
  or been moved out of Incoming.
  The following information may help to resolve the situation:
  
  The following packages have unmet dependencies:
  libudev-dev : Depends: libudev0 (= 175-0ubuntu9) but 175-0ubuntu9.3 is to be installed
  E: Unable to correct problems, you have held broken packages.
  </code></pre>
  
  <p>This seems to imply I should install libudev0, so:</p>
  
  <pre><code>sudo apt-get install libudev0
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  libudev0 is already the newest version.
  0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
  </code></pre>
  
  <p>I'm not sure how to proceed from here. libudev-dev depends on libudev0 but that's already in place, so ... what's next?</p>
  
  <p>Note that the following repos are un-commented in sources.list and I've done an apt-get update:</p>
  
  <pre><code>deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted    
  deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted
  deb http://us.archive.ubuntu.com/ubuntu/ precise universe
  deb-src http://us.archive.ubuntu.com/ubuntu/ precise universe
  </code></pre>
  
  <p>Some sites have indicated I should do -f:</p>
  
  <pre><code>sudo apt-get -f install 
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
  </code></pre>
  
  <p>Found an excellent link here:
      <a href="https://askubuntu.com/questions/140246/how-do-i-resolve-unmet-dependencies">https://askubuntu.com/questions/140246/how-do-i-resolve-unmet-dependencies</a>
  but no joy.</p>
  
  <p>Google says that this is a slam dunk for other folks out there...</p>
  
  <p>Thanks for any help on this,
  John</p>