# Build loadable extension with my own shared library

**URL:** <https://discourse.slicer.org/t/build-loadable-extension-with-my-own-shared-library/33988>\
**Category:** Development\
**Created:** [January 26, 2024, 9:36am UTC](https://discourse.slicer.org/t/build-loadable-extension-with-my-own-shared-library/33988 "2024-01-26T09:36:06Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![nnzzll](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/nnzzll/32/16350_2.png) [@nnzzll](https://discourse.slicer.org/u/nnzzll)\
**Post date:** [January 26, 2024, 9:36am UTC](https://discourse.slicer.org/t/build-loadable-extension-with-my-own-shared-library/33988/1 "2024-01-26T09:36:06Z")

</div>

I’m developing a loadable extension.

As I know, a C++ loadable extension has three part: `vtkSlicer${Module_Name}ModuleLogic`, `qSlicer${MODULE_NAME}ModuleWidgets`, and the module itself.

If I build moduleLogic or ModuleWidgets with my own shared libraries, CMake will throw an error below  
`export called with target "*ModuleWidgets/ModuleLogic*" which requires target "*SomeSharedLibrary*" that is not in any export set.`

My `CMakeLists.txt` for ModuleWidgets is shown below.  
It works fine when I link a library to module,but doesn’t work when link to logic or widgets.

```auto
project(qSlicer${MODULE_NAME}ModuleWidgets)

set(KIT ${PROJECT_NAME})

set(${KIT}_EXPORT_DIRECTIVE "Q_SLICER_MODULE_${MODULE_NAME_UPPER}_WIDGETS_EXPORT")

set(${KIT}_INCLUDE_DIRECTORIES
  )

set(${KIT}_SRCS
...
  )

set(${KIT}_MOC_SRCS
  qSlicer${MODULE_NAME}FooBarWidget.h
...
  )

set(${KIT}_UI_SRCS
  ../Resources/UI/qSlicer${MODULE_NAME}FooBarWidget.ui
...
  )

set(${KIT}_RESOURCES
  ../Resources/qSlicer${MODULE_NAME}Module.qrc
  )

set(${KIT}_TARGET_LIBRARIES
  vtkSlicer${MODULE_NAME}ModuleLogic
  SomeSharedLibary
  )

#-----------------------------------------------------------------------------
SlicerMacroBuildModuleWidgets(
  NAME ${KIT}
  EXPORT_DIRECTIVE ${${KIT}_EXPORT_DIRECTIVE}
  INCLUDE_DIRECTORIES ${${KIT}_INCLUDE_DIRECTORIES}
  SRCS ${${KIT}_SRCS}
  MOC_SRCS ${${KIT}_MOC_SRCS}
  UI_SRCS ${${KIT}_UI_SRCS}
  TARGET_LIBRARIES ${${KIT}_TARGET_LIBRARIES}
  RESOURCES ${${KIT}_RESOURCES}
  WRAP_PYTHONQT
  )

```

How can I fix this problem?