How to control Fortran warnings during compilation

By default Snek5000 suppresses the compilation warnings. This is because Nek5000 uses a lot of legacy tricks to achieve high performance which triggers warnings in modern C and Fortran compilers.

To display the warnings one should adjust the verbosity keyword argument for Output.update_snakemake_config. For example in your solver’s Snakemake file

from snek5000 import ensure_env, get_snek_resource
from snek5000_canonical import short_name, Output

configfile: "config_simul.yml"

Output.update_snakemake_config(config, short_name, verbosity=1)

How to halt compilation if Fortran warnings arise from case file (*.usr)

Fortran warnings from Nek5000 code-base maybe inevitable, but it is indeed possible to keep the case file tidy and subject to a stricter set of Fortran convention.