# Building Debug on Window
**URL:** https://discourse.kitware.com/t/building-debug-on-window/770
**Category:** Build & Install
**Created:** [February 4, 2022, 10:16pm UTC](https://discourse.kitware.com/t/building-debug-on-window/770 "2022-02-04T22:16:51Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Stan\_Hammon](https://discourse.kitware.com/u/Stan_Hammon)
#### Post date: [February 4, 2022, 10:16pm UTC](https://discourse.kitware.com/t/building-debug-on-window/770/1 "2022-02-04T22:16:51Z")
# General Setting
My goal is to build `smtk` (and later, `cmb`) in `Debug`. The problem is that `cmb-superbuild` does not allow `Debug` builds.
To work around this limitation, I want to build `cmb-superbuild` in `RelWithDebugInfo`, while also setting:
- `/MDd /DWIN32` compiler flags
- `_ITERATOR_DEBUG_LEVEL=0` (in the downstream projects, not `cmb-superbuild`)
As I understand it, this should allow the subsequent build of `smtk` to be `Debug`, even though `smb-superbuild` is built in `RelWithDebInfo`.
# Steps Taken
## `_ITERATOR_DEBUG_LEVEL`
The command line argument `-D_ITERATOR_DEBUG_LEVEL=0` does not seem to work, and instead the following line needs to be added to the main `CMakeLists.txt` file:
```auto
add_definitions(-D_ITERATOR_DEBUG_LEVEL=0)
```
It is unclear to me so far whether it is better to:
1. set `_ITERATOR_DEBUG_LEVEL=2` in `cmb-superbuild`, or
2. set `_ITERATOR_DEBUG_LEVEL=0` in `smtk` (and later, `cmb`)
I have not yet had a chance to test these two options.
## `/MDd /DWIN32` compiler flags
These compiler flags are set using these `cmake` commands:
```auto
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MDd /DWIN32")
set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /MDd /DWIN32")
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} /MDd /DWIN32")
```
The `/MDd` does not seem to propagate, and so must be set at every level of `cmb-superbuild`. So far, these lines of code are added to:
- CMakeLists.txt
- projects\paraview.cmake
- projects\vtk.cmake
- projects\vtkonly.cmake
- projects\win32\moab.cmake
- superbuild\projects\win32\boost.cmake
# Problem
For most parts of `cmb-superbuild`, the above steps work well. However, this fails for `VTK` within `paraview`. Specifically, we get hundreds/thousands of compile errors like:
```auto
cl : Command line warning D9025 : overriding '/MDd' with '/MD'
```
I cannot find any other likely locations where I should insert the compiler flags definitions to get past these compile errors.
How can I prevent `paraview` from overriding my specified flags?
---
### Author:  [@Stan\_Hammon](https://discourse.kitware.com/u/Stan_Hammon)
#### Post date: [February 4, 2022, 10:17pm UTC](https://discourse.kitware.com/t/building-debug-on-window/770/2 "2022-02-04T22:17:27Z")
@ben.boeckel Can you take a look at this?
---
### Author:  [@ben.boeckel](https://discourse.kitware.com/u/ben.boeckel)
#### Post date: [February 6, 2022, 4:52pm UTC](https://discourse.kitware.com/t/building-debug-on-window/770/3 "2022-02-06T16:52:48Z")
> [@Stan\_Hammon](#):
>
> `/DWIN32`
This is pointless. Don’t set it. It is really spelled `_WIN32` and is set by any sensible compiler. Anything relying on `WIN32` should be fixed.
> [@Stan\_Hammon](#):
>
> The command line argument `-D_ITERATOR_DEBUG_LEVEL=0` does not seem to work
Why would it? That sets a CMake variable (about which nothing cares about).
> [@Stan\_Hammon](#):
>
> These compiler flags are set using these `cmake` commands:
MSVC runtime is now selected by the [`MSVC_RUNTIME_LIBRARY`](https://cmake.org/cmake/help/latest/prop_tgt/MSVC_RUNTIME_LIBRARY.html) property. Do not set it via flags manually. Instead, you can use the `CMAKE_MSVC_RUNTIME_LIBRARY` variable. Note that projects which are not aware of CMake 3.15 will ignore this. We should make these projects CMP0091-aware instead.
> [@Stan\_Hammon](#):
>
> However, this fails for `VTK` within `paraview`. Specifically, we get hundreds/thousands of compile errors like:
>
> ```auto
> cl : Command line warning D9025 : overriding '/MDd' with '/MD'
>
> ```
>
> I cannot find any other likely locations where I should insert the compiler flags definitions to get past these compile errors.
This is because these projects are CMP0091-aware and do not expect the runtime to be set manually outside of the property.
---
### Author:  [@Stan\_Hammon](https://discourse.kitware.com/u/Stan_Hammon)
#### Post date: [February 16, 2022, 5:56pm UTC](https://discourse.kitware.com/t/building-debug-on-window/770/4 "2022-02-16T17:56:38Z")
Given the advice above (and recent progress with building `libarchive` in `Debug`), I’ve shifted back to trying to build all needed parts of `cmb-superbuild` in `Debug` rather than pursuing a hybrid approach.
To that end, I need to be able to build the following parts of `cmb-superbuild` in order to move on to building `smtk` (for further use building `cmb`):
- boost
- libarchive
- moab
- nlohmannjson
- paraview
- pegtl
- pybind11
I’m trying to build the smaller modules before moving on to `paraview`. So far, they all build in `Debug` except for `moab`.
The `moab` build fails within `netcdf` due to an error in `hdf5`. Here is the specific error from `netcdf-build-err.log`:
```auto
ninja: error: 'C:/projects/cmb-BenMR/5_15_2_VS19_64D/install/lib/hdf5.lib', needed by 'liblib/netcdf.dll', missing and no known rule to make it
CMake Error at C:/projects/cmb-BenMR/5_15_2_VS19_64D/superbuild/sb-netcdf-build.cmake:47 (message):
Failed with exit code 1
```
There is a `hdf5_D.lib` present in the build directory, but no `hdf5.lib`.
Do you have any advice or suggestions in regard to this error?