# Slicer nightly does not build with Qt4/VTK7

**URL:** <https://discourse.slicer.org/t/slicer-nightly-does-not-build-with-qt4-vtk7/2631>\
**Category:** Support\
**Created:** [April 19, 2018, 9:57am UTC](https://discourse.slicer.org/t/slicer-nightly-does-not-build-with-qt4-vtk7/2631 "2018-04-19T09:57:58Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ihnorton/32/9_2.png) [@ihnorton](https://discourse.slicer.org/u/ihnorton)\
**Post date:** [April 19, 2018, 2:04pm UTC](https://discourse.slicer.org/t/slicer-nightly-does-not-build-with-qt4-vtk7/2631/4 "2018-04-19T14:04:27Z")

</div>

I’ve seen some discussion of the `undeclared identifier` problem, but I thought that had been fixed with a DCMTK update.

If you don’t have a reason to use Qt4, I would suggest starting with Qt5, because that is the most maintained/tested now, and will build everything with C++11. I am successfully building on macOS 10.12 against Qt 5.10.1 from [http://download.qt.io/official\_releases/qt/5.10/5.10.1/](http://download.qt.io/official_releases/qt/5.10/5.10.1/)

If you do need Qt4 then somebody can try to debug, but otherwise please try Qt5 using [these instructions](https://www.slicer.org/wiki/Documentation/Labs/Qt5-and-VTK8#Status). eg on my computer:

```auto
cd /opt/bld/r/r5nj
ccmake -DQt5_DIR=/opt/sw/Qt_ol/5.10.1/clang_64/lib/cmake/Qt5 ~/git/s5

```

note that the base path for your build should be a relatively short path, in order to avoid errors described [here](https://discourse.slicer.org/t/macos-sierra-10-12-6-dynamic-linker-errors/2339). I would suggest staying under about 20 characters or so.

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