overlay class_loader, cannot catkin_make

edit

I am trying to overlay http://wiki.ros.org/class_loader in my environment. As far as I can tell, it's a catkin package, so I've cloned the git repo into the src directory of my catkin workspace.

First it was complaining about the cmake_modules package. It didn't look like I had that ros package, so I just checked out its source too. Now it's not complaining about that anymore.

I am on Groovy and Ubuntu 12.04. I have the ubuntu package libpoco-dev already installed.

Here are the current complaints:

-- +++ processing catkin package: 'cmake_modules'
-- ==> add_subdirectory(cmake_modules)
-- +++ processing catkin package: 'class_loader'
-- ==> add_subdirectory(class_loader)
CMake Error at class_loader/CMakeLists.txt:10 (find_package):
  Could not find module FindPoco.cmake or a configuration file for package
  Poco.

  Adjust CMAKE_MODULE_PATH to find FindPoco.cmake or set Poco_DIR to the
  directory containing a CMake configuration file for Poco.  The file will
  have one of the following names:

    PocoConfig.cmake
    poco-config.cmake



CMake Error at /opt/ros/groovy/share/catkin/cmake/catkin_package.cmake:159 (message):
  catkin_package() DEPENDS on 'Poco' which must be find_package()-ed before.
  If it is a catkin package it can be declared as CATKIN_DEPENDS instead
  without find_package()-ing it.
Call Stack (most recent call first):
  /opt/ros/groovy/share/catkin/cmake/catkin_package.cmake:98 (_catkin_package)
  class_loader/CMakeLists.txt:11 (catkin_package)


-- Configuring incomplete, errors occurred!
make: *** [cmake_check_build_system] Error 1
Invoking "make cmake_check_build_system" failed

EDIT:

I hadn't checked out the groovy-devel branch. Now when try to build, it gets further and eventually produces the following errors:

In file included from /home/goretkin/code/catkin_ws/src/pluginlib/include/pluginlib/class_loader.h:301:0,
                 from /home/goretkin/code/catkin_ws/src/pluginlib/src/plugin_tool.cpp:30:
/home/goretkin/code/catkin_ws/src/pluginlib/include/pluginlib/class_loader_imp.h: In member function ‘std::vector<std::basic_string<char> > pluginlib::ClassLoader<t>::getPluginXmlPaths(const string&, const string&, bool)’:
/home/goretkin/code/catkin_ws/src/pluginlib/include/pluginlib/class_loader_imp.h:182:72: error: no matching function for call to ‘getPlugins(const string&, const string&, std::vector<std::basic_string<char> >&, bool&)’
/home/goretkin/code/catkin_ws/src/pluginlib/include/pluginlib/class_loader_imp.h:182:72: note: candidates are:
/opt/ros/groovy/include/ros/package.h:108:18: note: void ros::package::getPlugins(const string&, const string&, ros::package::V_string&)
/opt/ros/groovy/include/ros/package.h:108:18: note:   candidate expects 3 arguments, 4 provided
/opt/ros/groovy/include/ros/package.h:114:18: note: void ros::package::getPlugins(const string&, const string&, ros::package::M_string&)
/opt/ros/groovy/include/ros/package.h:114:18: note:   candidate expects 3 arguments, 4 provided
make[2]: *** [pluginlib/CMakeFiles/plugin_tool.dir/src/plugin_tool.cpp.o] Error 1
make[1]: *** [pluginlib/CMakeFiles/plugin_tool.dir/all] Error 2
make: *** [all] Error 2
Invoking "make" failed

Presumably I have to also pull the latest ros/package.h?