Root 6.22/02 Ubuntu 20.04 armv7

Hi everybody,

I succeeded to install from source Root 6.22/02 on an Odroid XU4 (armv7, 32 bits) running Ubuntu 20.04 LTS. The “.demo” functions as well as my own Gui´s are “correctly” running out of one small quite annoying thing: the generated windows are transparent, non-black background or another window under makes the reading of the root-windows text uncomfortable. Before digging further, I am just asking around whether someone experienced such behavior? (no Problem with other Guis, like wxWidgets based).

Thanks a lot for any info.

_ROOT Version: 6.22/02
_Platform: armv7l 32 bits, Ubunu 20.04 LTS

Hi Faouzi,

This seems to be more related to the X11 configuration than the architecture. Can you paste the output of dpkg -l | grep -i x11?

@couet Have you seen such behavior before?


No… I never heard about that. It looks like a GUI issue. May by @bellenot heard of that. Can you provide a screen dump showing this effect ?

Hi everybody,

thanks a lot for the prompt answers.
@Jacob: here is the output x11_grep.txt (8.8 KB)
@Olivier: here are several screenshots showing 2 functions of the “.demo”.

Thanks again for your time and help.

Thanks for the screen shots. I see this transparency even with TCanvas…
I have no idea from where it is coming from … Is that new ? was it working before ?
Do you get this problem only from .demo ?
What do you get when you create a simple TCanvas ? do you have the same issue ?

Hi Olivier, hi everybody,

Root 5.34.30 (apt installed from ready .deb files) was perfectly running on Odroid U3 with Ubuntu 16.04 LTS. I was technicaly obliged to upgrade to the stronger platform Odroid XU4.
To get a clearer picture I installed Ubuntu 18.04 LTS on the XU4 and succeeded to install (with the outdated .deb files) Root 5.34.30. Everything works nice, no problem at all.
On this Platform with Ubuntu 20.04 LTS, I could not install Root 5 neither from the .deb files nor from source, both require old packages. So my only chance is Root 6.
All “.demo” function-Windows are transparent including my own Guis. wxWidgets based Guis are not affected.
I would like to give it another try with an early version of Root 6, which one do you recommend?


I guess it has something to do with the compositor in Ubuntu, making transparent any window that is made with some toolkit (e.g. Tcl/Tk,… I don’t know what ROOT uses) - it could even be that not only ROOT is being affected, but you still haven’t run other apps that do have the issue.
This, for example, seems a bit similar (using a dark theme, as you are too).

Hi Dastudillo,

thanks a lot. I will check this immediately.


Hi everybody,

Dastudillo got it. This issue ist not Root 6, it is an Ubuntu 20.04 background problem. To fix it with “Mate” window manager just do the following:

  1. go to “Mate-Tweak” in “Control-Center” (please install when not available)
  2. go there to Windows
  3. set there the Window-manager to “Marco (no composite)”.

Many thanks for your help,
PS: the issue can be closed with “solved” status.

1 Like

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.