# Can't start latest stable on ubuntu 20.04

**URL:** <https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029>\
**Category:** Support\
**Created:** [October 14, 2020, 3:58am UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029 "2020-10-14T03:58:21Z")\
**Posts on this page:** 20\
**Page:** 2

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**Author:** ![RafaelPalomar](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rafaelpalomar/32/1436_2.png) [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Post date:** [December 3, 2020, 8:33pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/21 "2020-12-03T20:33:00Z")

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@pieper `qt5dxcb-plugin` seems to be a component of QtGui that can be built with the `-qt-xcb` flag ([Qt XCB](https://doc.qt.io/qt-5.9/qtgui-attribution-xcb.html)). I guess to include this in the slicer packaging QT should be included as a whole? I’m with you on avoiding the user installing packages to use the packaged binaries, but we need to be careful not ending up packaging all the way to the Linux kernel 😉

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**Author:** ![manjula](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/manjula/32/80981_2.png) [@manjula](https://discourse.slicer.org/u/manjula)\
**Post date:** [December 3, 2020, 8:39pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/22 "2020-12-03T20:39:00Z")

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> [@RafaelPalomar](#):
>
> - [Error 2] Slicer crashes with a segmentation fault on application launch. It seems the crash produces on the interaction of python (ctypes extension) with libffi ( `/usr/lib/x86_64-linux-gnu/libffi.so.8` ). In Ubuntu 20.10 libffi is packaged in its 3.4 version, while in other distributions not having this problem the version is 3.3. This would suggest incompatibility between the python deployed in Slicer and libffi installed in Ubuntu 20.10; @manjula, could you check the version of libffi in PoP OS 20.10 just to discard this end?

3.4~20200819gead65ca871-0ubuntu3

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**Author:** ![RafaelPalomar](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rafaelpalomar/32/1436_2.png) [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Post date:** [December 3, 2020, 9:13pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/23 "2020-12-03T21:13:28Z")

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thanks @manjula. It is exactly the same version as in Ubuntu 20.10. We may not be hitting the right diagnostic here with the compatibility. Would you mind to paste a list of your installed packages in [dpaste](https://dpaste.org)?

to do this you can install `xclip`:

```auto
sudo apt install xclip

```

and then copy the list of packages in the clipboard

```auto
sudo apt list --installed | xclip -selection c

```

thenk you can go to [dpaste](https://dpaste.org), paste (Ctrl+V) the results and post here the link. If PoP is almost Ubuntu, maybe we find the difference.

Thanks in advance.

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**Author:** ![manjula](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/manjula/32/80981_2.png) [@manjula](https://discourse.slicer.org/u/manjula)\
**Post date:** [December 3, 2020, 9:24pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/24 "2020-12-03T21:24:21Z")

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Please note that most of my packages i have is in flatpak but here is the link.

> **[dpaste/sNOh (Python)](https://dpaste.org/sNOh)**

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**Author:** ![manjula](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/manjula/32/80981_2.png) [@manjula](https://discourse.slicer.org/u/manjula)\
**Post date:** [December 3, 2020, 9:28pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/25 "2020-12-03T21:28:08Z")

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I mentioned about flatpak because when I was figuring out what was going wrong with linkSlicerBlender the deb version of the Blender was giving error in importing numpy, Apparently it was a know issue with blender but when i switch to flatpak it went away.

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**Author:** ![RafaelPalomar](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rafaelpalomar/32/1436_2.png) [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Post date:** [December 6, 2020, 6:54am UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/26 "2020-12-06T06:54:14Z")

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I have installed PopOS 20.10 (also the packages from @manjula) and got the same results as with Ubuntu 20.10:

- Error due to missing `libxcb-xinerama0` on Slicer stable (`4.11.20200930`). When `libxcb-xinerama0` is installed, segmentation fault is produced on startup.
- Segmentation fault is removed by compiling python with `BUILTIN_CTYPES=ON`.

I still think the problem is leaning towards a compatibility problem between python and libffi 3.4.

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**Author:** ![kotloski](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/kotloski/32/9115_2.png) [@kotloski](https://discourse.slicer.org/u/kotloski)\
**Post date:** [December 8, 2020, 3:54pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/27 "2020-12-08T15:54:04Z")

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I think I am experiencing the same issue with Ubuntu 20.10. Can you tell me how to use the BUILTIN\_CTYPES=ON work-around? I have not been able to figure it out from the online documentation. Thanks!

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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:** [December 8, 2020, 7:04pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/28 "2020-12-08T19:04:13Z")

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> [@kotloski](#):
>
> Can you tell me how to use the BUILTIN\_CTYPES=ON work-around?

This is a build option for the `cpython-cmake-buildsystem` project, you can enable this option adding

```auto
-DBUILTIN_CTYPES=ON

```

under `CMAKE_CACHE_ARGS` in this file:

> <https://github.com/Slicer/Slicer/blob/de2e43a7271b2f72d5537ea0a9af1288beb44055/SuperBuild/External_python.cmake#L138>

Then, you would have to re-build Slicer from the top-level.

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**Author:** ![kotloski](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/kotloski/32/9115_2.png) [@kotloski](https://discourse.slicer.org/u/kotloski)\
**Post date:** [December 10, 2020, 2:17pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/29 "2020-12-10T14:17:50Z")

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Thanks! Adding **-DBUILTIN\_CTYPES:BOOL=ON** worked. Though the extension I need doesn’t won’t run in the latest build. Oh well, it’s been that kind of year.

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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:** [December 10, 2020, 3:51pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/30 "2020-12-10T15:51:24Z")

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> [@kotloski](#):
>
> Though the extension I need doesn’t won’t run in the latest build.

Which extension it is ?

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<div class="post-metadata">

**Author:** ![kotloski](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/kotloski/32/9115_2.png) [@kotloski](https://discourse.slicer.org/u/kotloski)\
**Post date:** [December 10, 2020, 4:29pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/31 "2020-12-10T16:29:01Z")

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Segmentation Wizard. It last worked for me in 4.10.2. The extension seems to install OK and I can see it in the Extensions manager window, but I can not find it under modules in the main program and it is listed as “not loaded” when I search using Module finder. Thanks for any help; I just need to finish up a little bit of old data.

> **[Documentation/Nightly/Extensions/SegmentationWizard - Slicer Wiki](https://www.slicer.org/wiki/Documentation/Nightly/Extensions/SegmentationWizard)**

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**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:** [December 10, 2020, 7:59pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/32 "2020-12-10T19:59:09Z")

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Yes. Your system is not compatible with the precompiled binaries that we provide.

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**Author:** ![manjula](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/manjula/32/80981_2.png) [@manjula](https://discourse.slicer.org/u/manjula)\
**Post date:** [December 14, 2020, 1:24pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/33 "2020-12-14T13:24:54Z")

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I today tried building Slicer in Manjaro Linux on a fresh install. it failed, with the following errors.

This is the output from the finals parts

[https://pastebin.com/0gAANfae](https://pastebin.com/0gAANfae)

As @RafaelPalomar said i checked the version of libffi

> core/libffi 3.3-4 [installed]  
> Portable foreign function interface library  
> community/haskell-libffi 0.1-20  
> A binding to libffi  
> multilib/lib32-libffi 3.3-2 [installed]  
> A portable, high level programming interface to various calling conventions (32-bit)

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**Author:** ![RafaelPalomar](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rafaelpalomar/32/1436_2.png) [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Post date:** [December 14, 2020, 3:51pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/34 "2020-12-14T15:51:08Z")

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@manjula, I think your problem is not related to the issue discussed in this thread. This thread is starting to be a mix of different issues and is becoming difficult to follow. I suggest that you open a new thread for discussing it.

Regards,  
Rafael

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**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:** [December 14, 2020, 4:00pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/35 "2020-12-14T16:00:18Z")

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It may be better to keep this thread as general discussion topic here and create separate issues in the issue tracker to discuss technical details there.

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**Author:** ![fuentesdt](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/fuentesdt/32/9361_2.png) [@fuentesdt](https://discourse.slicer.org/u/fuentesdt)\
**Post date:** [December 29, 2020, 4:01am UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/36 "2020-12-29T04:01:56Z")

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apt-get install libxcb-xinerama0-dev

seemed to work for me on ubuntu 16.04

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**Author:** ![Karam\_AbuGhalieh](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/karam_abughalieh/32/9855_2.png) [@Karam\_AbuGhalieh](https://discourse.slicer.org/u/Karam_AbuGhalieh)\
**Post date:** [February 9, 2021, 5:09pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/37 "2021-02-09T17:09:45Z")

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I found this solution [here](https://askubuntu.com/questions/308128/failed-to-load-platform-plugin-xcb-while-launching-qt5-app-on-linux-without) and worked fine for me:

```auto
sudo apt-get install --reinstall libxcb-xinerama0

```

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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:** [February 9, 2021, 5:47pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/38 "2021-02-09T17:47:05Z")

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Thank you. This is also described in the [Slicer install instructions](https://slicer.readthedocs.io/en/latest/user_guide/getting_started.html#linux).

@Karam_AbuGhalieh Do you have a suggestion how to make the instructions easier to find?

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<div class="post-metadata">

**Author:** ![Karam\_AbuGhalieh](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/karam_abughalieh/32/9855_2.png) [@Karam\_AbuGhalieh](https://discourse.slicer.org/u/Karam_AbuGhalieh)\
**Post date:** [February 9, 2021, 7:22pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/39 "2021-02-09T19:22:56Z")

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I was there before facing the problem, now I am surprised the solution is there!

I think what I did is just reading the Linux section and ignoring the next Debian/Ubuntu one!!

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [December 18, 2021, 4:49pm UTC](https://discourse.slicer.org/t/cant-start-latest-stable-on-ubuntu-20-04/14029/40 "2021-12-18T16:49:47Z")

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Note that for another machine where I started from a fresh unbuntu 20.04 that wasn’t configured as a desktop workstation I also needed to add this package to get past the xcb startup issue: `sudo apt-get install libxcb-shape0`

I also installed these packages to get xvfb-run to work with Slicer:

`sudo apt-get install libxcb-icccm4-dev libxcb-image0-dev libxcb-keysyms1-dev libxcb-randr0 libxcb-render-util0 libxcb-xkb-dev libxkbcommon-x11-dev`

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