# Missing header files
**URL:** https://discourse.paraview.org/t/missing-header-files/12117
**Category:** ParaView Support
**Created:** [May 16, 2023, 8:01pm UTC](https://discourse.paraview.org/t/missing-header-files/12117 "2023-05-16T20:01:05Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@EdK](https://discourse.paraview.org/u/EdK)
#### Post date: [May 16, 2023, 8:01pm UTC](https://discourse.paraview.org/t/missing-header-files/12117/1 "2023-05-16T20:01:05Z")
I am trying to build ParaView with Catalyst and Python enabled. My compilation is successful, but an application that includes some ParaView header files gets stuck because some expected files are not found. For example, the files in Clients/PythonCatalyst include a file called vtkPVPythonCatalystModule.h which is not found. I am guessing that this file is not being generated due to an error in my CMake parameters, but I can’t see what is missing. Any ideas or do you know where this file should be coming from?
Thanks,
Ed
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### Author:  [@ben.boeckel](https://discourse.paraview.org/u/ben.boeckel)
#### Post date: [May 17, 2023, 11:12am UTC](https://discourse.paraview.org/t/missing-header-files/12117/2 "2023-05-17T11:12:00Z")
A few clarifying questions:
- Are you adding `-I` flags manually, using CMake, or `paraview-config`? (the last two should handle this already)
- Did you install ParaView or using its build tree? (if the latter, it lives in the build tree, not the source tree)
Note that ParaView would not build if that file were not there (it contains the `_EXPORT` symbols used to tell the compiler what classes should be accessible from the library)
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### Author:  [@EdK](https://discourse.paraview.org/u/EdK)
#### Post date: [May 22, 2023, 3:55pm UTC](https://discourse.paraview.org/t/missing-header-files/12117/3 "2023-05-22T15:55:03Z")
Hi Ben,
Thank you for your reply. I am building from the ParaView-v5.10.1.tar.gz tarball using gcc 9.3.0 with the CMake command:
cmake
-DCMAKE\_INSTALL\_PREFIX:PATH=${INSTALL}
-DCMAKE\_BUILD\_TYPE=Release
-DPARAVIEW\_USE\_QT:BOOL=OFF
-DPARAVIEW\_INSTALL\_DEVELOPMENT\_FILES=ON
$SRC\_DIR
My goal is to link with SENSEI which wants Catalyst and Catalyst Python scripts. I get to a point in the SENSEI build where I see
In file included from /xyz/ParaView-v5.10.1/Clients/PythonCatalyst/vtkCPPythonScriptPipeline.h:18,
from /abc/SENSEI-4.1.0/sensei/CatalystAnalysisAdaptor.cxx:42:
/xyz/ParaView-v5.10.1/Clients/PythonCatalyst/vtkCPPythonPipeline.h:19:10: fatal error: vtkPVPythonCatalystModule.h: No such file or directory
19 | #include “vtkPVPythonCatalystModule.h” // For windows import/export of shared libraries
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
Sure enough, there is no vtkPVPythonCatalystModule.h to be found anywhere. I figure I must be doing something wrong that is preventing that file from being generated.
Ed
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### Author:  [@ben.boeckel](https://discourse.paraview.org/u/ben.boeckel)
#### Post date: [May 29, 2023, 7:39pm UTC](https://discourse.paraview.org/t/missing-header-files/12117/4 "2023-05-29T19:39:50Z")
It’s not really clear why this is happening. It could just be a 5.10 thing, but I don’t think anything has changed near here in the module system since then. Is the `PythonCatalyst` library in the build/install tree?
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### Author:  [@EdK](https://discourse.paraview.org/u/EdK)
#### Post date: [June 14, 2023, 12:50am UTC](https://discourse.paraview.org/t/missing-header-files/12117/5 "2023-06-14T00:50:40Z")
> [@EdK](#):
>
> vtkPVPythonCatalystModule.h
Hello Ben,
I discovered that the problem is that I didn’t set the CMake variable PARAVIEW\_USE\_PYTHON. Apparently that is the trigger for generating vtkPVPythonCatalystModule.h. Thank you for checking into this problem for me.
Ed