# Debug Build errors 

**URL:** <https://discourse.slicer.org/t/debug-build-errors/28961>\
**Category:** Development\
**Created:** [April 17, 2023, 1:02pm UTC](https://discourse.slicer.org/t/debug-build-errors/28961 "2023-04-17T13:02:29Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![DRDMT](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@DRDMT](https://discourse.slicer.org/u/DRDMT)\
**Post date:** [April 17, 2023, 1:02pm UTC](https://discourse.slicer.org/t/debug-build-errors/28961/1 "2023-04-17T13:02:29Z")

</div>

Hello Team,  
How can we debug or find more information about the error messages created while building a module.  
I am just trying to create a new node. When ever I call a New() method I get the error below:

```auto
6>vtkSlicer<Module>Logic.cxx
6> Creating library C:/D/SE/<Extension>/build/lib/Slicer-5.3/qt-loadable-modules/Debug/vtkSlicer<Module>ModuleLogic.lib and object C:/D/SE/<Extension>/build/lib/Slicer-5.3/qt-loadable-modules/Debug/vtkSlicer<Module>ModuleLogic.exp
6>vtkSlicer<Module>Logic.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static class vtkMRML<Module>Node *__cdecl vtkMRML<Module>Node::New(void)" (__imp_?New@vtkMRML<Module>Node@@SAPEAV1@XZ) referenced in function "protected: virtual void__cdecl vtkSlicer<Module>Logic::RegisterNodes(void)" (?RegisterNodes@vtkSlicer<Module>Logic@@MEAAXXZ)
6> Hint on symbols that are defined and could potentially match:
6> "__declspec(dllimport) public: static class vtkIntArray *__cdecl vtkIntArray::New(void)" (__imp_?New@vtkIntArray@@SAPEAV1@XZ)
6>C:\D\SE\<Extension>\build\lib\Slicer-5.3\qt-loadable-modules\Debug\vtkSlicer<Module>ModuleLogic.dll : fatal error LNK1120: 1 unresolved externals
6>Done building project "vtkSlicer<Module>ModuleLogic.vcxproj" -- FAILED.

```

Regards

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<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [April 17, 2023, 1:04pm UTC](https://discourse.slicer.org/t/debug-build-errors/28961/2 "2023-04-17T13:04:23Z")

</div>

It seems that in the CMakeLists.txt you missed listing the library that provides the `vtkMRML<Module>Node` node. Follow the example of modules that register new node types.

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<div class="post-metadata">

**Author:** ![DRDMT](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@DRDMT](https://discourse.slicer.org/u/DRDMT)\
**Post date:** [April 17, 2023, 7:19pm UTC](https://discourse.slicer.org/t/debug-build-errors/28961/3 "2023-04-17T19:19:23Z")

</div>

Kindly could you give a link of one such module. Also this is the CMakeLists.txt file in MRML folder right?

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<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [April 17, 2023, 7:20pm UTC](https://discourse.slicer.org/t/debug-build-errors/28961/4 "2023-04-17T19:20:41Z")

</div>

Most modules are like that. Search for `RegisterNodes`.