How does snakemake --show-failed-logs works - snakemake

Question

I want to use snakemake with the --show-failed-logs parameter but not sure how it works or what to expect.
For example (not a working example I just typed and copied some code parts, if necessary I can create a working example)
My command is:
snakemake -s Snakefile_test.smk --configfile test.yml -j 4 --restart-times 2 --show-failed-logs
In Snakefile_test.smk I have a rule:
rule testrule:
input:
R1_trimmed = rules.trim.output.R1_trimmed,
R2_trimmed = rules.trim.output.R2_trimmed
output:
plot_R1 = output+"/{sample}/figures/{sample}_R1_plot.png",
plot_R2 = output+"/{sample}/figures/{sample}_R2_plot.png",
log:
testrule_log = output+"/{sample}/logs/plot_log.txt"
run:
shell("python scripts/createplot.py -r1_trimmed {input.R1_trimmed} -r2_trimmed {input.R2_trimmed} -plot_r1 {output.plot_R1} -plot_r2 {output.plot_R2} -log {log.testrule_log}")
In createplot.py to test I have something like:
if __name__ == "__main__":
logging.basicConfig(filename=args.log, level=logging.DEBUG, format='%(asctime)s %(levelname)s %(name)s %(message)s')
logger=logging.getLogger(__name__)
#to add some content to the log file
try:
1/0
except ZeroDivisionError as err:
logger.error(err)
main()
#to let the script crash
a = 1/0
Because obviously createplot.py will crash the pipeline I expected that snakemake would print the contents of testrule_log to the screen. But that is not the case. I am using version 5.25.0
EDIT:
I am familiar with
script:
"scripts/createplot.py"
But need to use shell in this case. If that causes the problem let me know.