# Build Slicer with ubuntu 20.04, Qt5.15, cmake 3.17.3

**URL:** <https://discourse.slicer.org/t/build-slicer-with-ubuntu-20-04-qt5-15-cmake-3-17-3/11925>\
**Category:** Development\
**Tags:** build, qt, linux\
**Created:** [June 8, 2020, 12:09pm UTC](https://discourse.slicer.org/t/build-slicer-with-ubuntu-20-04-qt5-15-cmake-3-17-3/11925 "2020-06-08T12:09:21Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Davide\_Punzo](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/davide_punzo/32/66104_2.png) [@Davide\_Punzo](https://discourse.slicer.org/u/Davide_Punzo)\
**Post date:** [June 8, 2020, 12:09pm UTC](https://discourse.slicer.org/t/build-slicer-with-ubuntu-20-04-qt5-15-cmake-3-17-3/11925/1 "2020-06-08T12:09:21Z")

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Hi guys,

I managed to build latest Slicer on ubuntu 20.04, Qt5.15, cmake 3.17.3, gcc 9.3.0, but I had two minor issues:

1. I had to set Slicer\_USE\_PYTHONQT\_WITH\_OPENSSL = OFF (Slicer was crashing in line [Slicer/qSlicerCoreApplication.cxx at 43a758c3d4a0b1568e505606166fd8f68d19095a · Slicer/Slicer · GitHub](https://github.com/Slicer/Slicer/blob/43a758c3d4a0b1568e505606166fd8f68d19095a/Base/QTCore/qSlicerCoreApplication.cxx#L265) )

2. Once I build the project and I try to load the inner-build folder (Slicer-build) in QtCreator (4.12.2), QtCreator will reconfigure the full Superbuild inside the inner-build and all the compilation of the inner-build will be compromised. Does anyone have a fix or a workaround?

Davide.

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**Author:** ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Post date:** [June 8, 2020, 1:23pm UTC](https://discourse.slicer.org/t/build-slicer-with-ubuntu-20-04-qt5-15-cmake-3-17-3/11925/2 "2020-06-08T13:23:28Z")

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> managed to build latest Slicer on ubuntu 20.04, Qt5.15, cmake 3.17.3, gcc 9.3.0

👍

> I had to set Slicer\_USE\_PYTHONQT\_WITH\_OPENSSL = OFF (Slicer was crashing in line [Slicer/Base/QTCore/qSlicerCoreApplication.cxx at 43a758c3d4a0b1568e505606166fd8f68d19095a · Slicer/Slicer · GitHub](https://github.com/Slicer/Slicer/blob/43a758c3d4a0b1568e505606166fd8f68d19095a/Base/QTCore/qSlicerCoreApplication.cxx#L265) )

We are long over due to an openssl update.  
By any change, do you have a more details stacktrace ?

> Once I build the project and I try to load the inner-build folder (Slicer-build) in QtCreator (4.12.2), QtCreator will reconfigure the full Superbuild inside the inner-build and all the compilation of the inner-build will be compromised. Does anyone have a fix or a workaround?

Based on my experience with older Qt Creator …

After building the project using `Makefile` or `Ninja` generator, did you make sure to open the inner-build project using Qt creator ?

While doing so, you also need to make sure that the compiler, qt version, … all match the one you used to build Slicer.

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**Author:** ![Davide\_Punzo](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/davide_punzo/32/66104_2.png) [@Davide\_Punzo](https://discourse.slicer.org/u/Davide_Punzo)\
**Post date:** [June 8, 2020, 1:44pm UTC](https://discourse.slicer.org/t/build-slicer-with-ubuntu-20-04-qt5-15-cmake-3-17-3/11925/3 "2020-06-08T13:44:40Z")

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> [@jcfr](#):
>
> We are long over due to an openssl update.  
> By any change, do you have a more details stacktrace ?

ok, I have cleaned the inner-build folder, as soon as I finished recompiling again, I’ll run gdb again.

> [@jcfr](#):
>
> After building the project using `Makefile` or `Ninja` generator, did you make sure to open the inner-build project using Qt creator ?

yes

> [@jcfr](#):
>
> While doing so, you also need to make sure that the compiler, qt version, … all match the one you used to build Slicer.

ok, in the past for me it was quite automatic and smooth, I’ll check the kit variables.

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<div class="post-metadata">

**Author:** ![Davide\_Punzo](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/davide_punzo/32/66104_2.png) [@Davide\_Punzo](https://discourse.slicer.org/u/Davide_Punzo)\
**Post date:** [June 8, 2020, 3:17pm UTC](https://discourse.slicer.org/t/build-slicer-with-ubuntu-20-04-qt5-15-cmake-3-17-3/11925/4 "2020-06-08T15:17:57Z")

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> [@jcfr](#):
>
> By any change, do you have a more details stacktrace ?

screenshot of the levels:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/7/2/72a2e209b195ffe5ac3964b964b9f11dc1a54f98.png)  
please let me know if you need variables or pointer info for some levels.

> [@jcfr](#):
>
> While doing so, you also need to make sure that the compiler, qt version, … all match the one you used to build Slicer.

It was indeed a wrong compiler version in the qtcreator kit (I should have checked 😄), thanks for the hint!