Find_package() unable to find packages that I've created in the workspace.

edit

I've been having a weird issue where I get the following error.

  Project 'gimbal_control' tried to find library 'mav_recv'.  The library is
  neither a target nor built/installed properly.  Did you compile project
  'mav_recv'? Did you find_package() it before the subdirectory containing
  its code is included?

When the existing ROS packages i.e. roscpp / nodelet that are in the find_library() function work fine. However when I include my package such as mav_recv or gstreamer_udp, it gives me the following error. The other 2 packages that are independent, build just fine by themselves. However, this package that is reliant on mav_recv messages gives me that cmake error. It seems that the find_library() function is unable to locate my packages in the current workspace, while it does find packages in the ROS workspace (I've installed ROS from source in ros_catkin_ws).

I've included both ROS workspaces in the /.bashrc file. And ROS is able to run the gstreamer_udp and mav_recv nodes when built individually. Here is my CMakeLists.txt for mav_recv,

cmake_minimum_required(VERSION 2.8.3)
project(mav_recv)
find_package(catkin REQUIRED COMPONENTS roscpp message_generation)

add_message_files(
    FILES
    Camera_mode.msg
    Gimbal_commands.msg
)

generate_messages()

catkin_package(
    INCLUDE_DIRS include
    LIBRARIES ${PROJECT_NAME}
    CATKIN_DEPENDS roscpp message_runtime
)

include_directories(include
                    # For mavlink messages
                    /home/pi/mavlink/include/uwa_grand_challenge
                    ${catkin_INCLUDE_DIRS})

add_executable(mav_recv_node src/mav_recv_node.cpp)
add_dependencies(mav_recv_node ${${PROJECT_NAME}_EXPORTED_TARGETS})

add_library(mav_recv_lib src/mav_recv.cpp)

target_link_libraries(
    mav_recv_node
    mav_recv_lib
    ${catkin_LIBRARIES}
)

and gimbal_control CMakeLists.txt,

cmake_minimum_required(VERSION 2.8.3)
project(gimbal_control)
find_package(catkin REQUIRED COMPONENTS roscpp mav_recv)

catkin_package(
    INCLUDE_DIRS include
    LIBRARIES ${PROJECT_NAME}
    CATKIN_DEPENDS roscpp mav_recv
)
include_directories(include ${catkin_INCLUDE_DIRS})

add_executable(gimbal_control_node src/gimbal_control_node.cpp)
add_dependencies(gimbal_control_node ${catkin_EXPORTED_TARGETS})

add_library(gimbal_control_lib src/gimbal_control.cpp src/i2c_bus.cpp)
add_dependencies(gimbal_control_lib ${catkin_EXPORTED_TARGETS})

target_link_libraries(
    gimbal_control_node
    gimbal_control_lib
    ${catkin_LIBRARIES}
)

Any help would really be appreciated as I've spent a long time on trying to get it to work.

Thanks,