Segmentation fault (core dumped) - error with Flair


I am using Ubuntu on a VM.
I had problems with flair crashing so decided to update to the newest version of Ubuntu - I still have the same issue…

I updated to Ubuntu20.4 and then had to reinstall flair. When I ran it, every time I opened geometry flair crashed with the error “Segmentation fault (core dumped)”

I uninstalled and tried to reinstall flair.
However when I did this I got the following error message…

(Reading database … 206734 files and directories currently installed.)
Preparing to unpack flair_3.1-4_ubuntu20.04_all.deb …
Unpacking flair (3.1-4) over (3.1-4) …
Preparing to unpack flair-geoviewer_3.1-4_ubuntu20.04_amd64.deb …
Unpacking flair-geoviewer (3.1-4) over (3.1-4) …
dpkg: dependency problems prevent configuration of flair:
flair depends on python3-scipy; however:
Package python3-scipy is not installed.

dpkg: error processing package flair (–install):
dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of flair-geoviewer:
flair-geoviewer depends on flair (= 3.1-4); however:
Package flair is not configured yet.

dpkg: error processing package flair-geoviewer (–install):
dependency problems - leaving unconfigured
Processing triggers for shared-mime-info (1.15-1) …
Processing triggers for gnome-menus (3.36.0-1ubuntu1) …
Processing triggers for desktop-file-utils (0.24-1ubuntu3) …
Processing triggers for mime-support (3.64ubuntu1) …
Processing triggers for hicolor-icon-theme (0.17-2) …
Errors were encountered while processing:

…I am guessing there is an issue with python3-scipy in the flair code?

I am totally new to this so any help would be appreciated.

Dear Fiona,

we are currently investigating the issue which causes Flair to crash in a virtual machine.

There is two workaround at the moment:

  1. Increase the number of CPUs assigned to the virtual machine to at least 4, or
  2. Set the number CPUs used by Geoviewer to 1. (Click the wrench icon at the bottom right corner, select 1 CPU/core on the Geomertry page, and finally restart Flair)

Doing one of them should prevent the crash.

Flair only uses scipy for the Dicom related functions, and it will show a clear error message if it is missing. This is unrelated to the crash.


Hi David

Ok, thank you. I have adjusted the CPUs and hopefully this will work.

For the error with python3-scipy is there anything I should do for this?


Dear Fiona,

you can simply install the python3-scipy package manually using apt.


OK thanks, much appreciated