Versions
FLUKA : 4-5.1
Flair : 3.4-5.2
Operating system : Fedora Linux 43
Compiler : gcc-gfortran.x86_64 15.2.1-4.fc43
Description
After updating my workstation to Fedora 43 flair crashes when switching to the “Geometry Tab”. This is independent of any input file as it also happens when having no project open (empty .inp file)
When I open flair from the shell I get the following error when switching to the “Geometry Tab”:
╭─lars@zenbook ~
╰─➤ flair 130 ↵
/usr/local/flair/flair: line 18: 224240 Segmentation fault (core dumped) ${PYTHON} -O -W ignore ${DIR}/flair.py "$@"
Input files
It does not depend on any input files since it happens also directly after startup (no files open or loaded).
I know this must be a version issue but I dont know how to find out which package or dependency is causing the issue. The error does not tell me much.
Any help on how to debug this is greatly appreciated.
Cheers,
Lars
ceruttif
(Francesco Cerutti)
24 November 2025 20:11
2
Hi Lars,
see this fresh answer and please confirm its effectiveness.
Dear Francesco
Thank you very much for the swift answer. I am sorry about the duplicate question, I was not aware of the other thread.
Installing python3.13 solved the issue for me, thank you so much!
If anyone has the same problem, I performed the following steps (Fedora 43) to solve the issue:
sudo dnf install python3.13 python3.13-tkinter python3.13-libs
Set the PYTHON variable in /usr/local/flair/flair to python3.13 with:
sudo nano /usr/local/flair/flair
I then also needed to install the pillow package in the python3.13 env with the following commands:
python3.13 -m ensurepip --upgrade
python3.13 -m pip install --upgrade pip
python3.13 -m pip install pillow
Do you know when this issue will be resolved or how I would hear about it? Normally, I track the GitHub or GitLab issues but I don’t see this option here.
Thank you again for your help.
Cheers,
Lars
ceruttif
(Francesco Cerutti)
11 December 2025 20:05
5
@mario.marengo2
It looks like this Fedora 43 pbm is now solved by the last system update.
Dear Francesco
Thank you for the update.
After updating my system and rebooting I set the PYTHON variable back to python3. But now flair does no longer launch and I get the following error:
╭─lars@zenbook ~
╰─➤ sudo nano /usr/local/flair/flair
╭─lars@zenbook ~
╰─➤ flair
/usr/local/flair/flair: line 18: 10249 Segmentation fault (core dumped) ${PYTHON} -O -W ignore ${DIR}/flair.py "$@"
It seems that the issue is not fixed yet?
Or is there another issue?
Thank you for all the help.
Cheers,
Lars
ceruttif
(Francesco Cerutti)
12 December 2025 13:22
8
Take the fresh flair-geoviewer package for FC43 from the Official flair site