Flair failure during start

Hello David,
I have a unique issue. I have installed Flair and flair-geoviewer-3.1.8(from source) on RHEL 8.2
From the installation on the same server I can run flair and start. Resulting no errors.
But another user on the same server having receiving an errors would not continue the “start” following “run”.

For me and user produces the similar “check-fluka.py” results on rhel 8.2 system:
‘check-fluka.py’ results:


Checking python
Version: 3.6-8 ok

Checking python tkinter module
tkinter found

Checking tk library
Tk Version= 8.6 ok

Checking python imaging
python-imaging-tk installed

Checking gnuplot
gnuplot 5.2.4 ok

Checking memory
Ram: 16116380 kb ok
Swap: 12582908 kb ok

Checking CPU
CPUs: 8 ok
Clock: 3760.8 MHz ok
Arch: x86_64

Checking X11
X11 dimension: 1843x974 ok
X11 depth: 24 ok

Checking flair
flair directory: /usr/local/flair
flair version: 3.1-8

Checking flair-geoviewer
flair version ok (same or higher than 3.0-7)
flair-geoviewer version 3.1-8
flair and geoviewer version match

Checking gfortran
Traceback (most recent call last):
File “./check_fluka.py”, line 511, in
f = open(“test.f”,“w”)
PermissionError: [Errno 13] Permission denied: ‘test.f’

I assume the errors at the end are benign msgs due to the fact I built fluka from the source using “gcc-gfortran-8.3.1-5.”.

Appreciate your input.


Dear Arthur,

it likely to be an permission error.

Please try to run FLUKA from the command line with

rfluka -M1 <inputfile>

Similarly, the check_fluka.sh doesn’t have permission to create the test.f file, in its directory.


Hello David,
Thanks for your feedback.
I couldn’t locate/find " check_fluka.sh".
What is the path for “check_fluka.sh” ?
Also, please let me know the path to “test.f”


Dear Arthur, the check_fluka.sh script is just a wrapper for check_fluka.py to create a log file, among others. You can download it from FLUKA Beginner Online Training (Oct 5-16, 2020) (5-16 October 2020): FLUKA and Flair installation check script · Indico.

The test.f is automatically generated by check_fluka.py in the directory where it is located.


Hi David,
Yes, that is correct I only have ‘check_fluka.ph’.
I think our working directory was the problem. We created a new directory then everything was fine, working! No errors with “check_fluka.py”.
I was wondering whether Fluka generated .* (dot files, i.e. hidden files). I looked but couldn’t find any.
Could that be in the user home dir?

I am thinking just in case in the future if I run into an issue how to clear the problem rather than deleting the directory.

Thanks for your help.

Dear Arthur,

Fluka doesn’t create any hidden files.

It could be that the previous directory was created as root, so the normal user account couldn’t access it. However you can always change the permission with the Linux command chmod.


HI David,

Thanks for your quick response.
No the directory was created by the user. File system has the correct ownerhip, i.e. user:user.
I didn’t have to chmod it… If this happen again then let’s debug the root cause.

Thanks for you help