...

> cd /glade/work/$USER/derecho_cases
> git clone https://github.com/ESCOMP/CESM.git cesm2_2_derecho
> cd cesm2_2_derecho
> git checkout cesm2.2-asdbranch

You should see in the $CESM_ROOT directory:

...

Download the model component source code.

> git checkout cesm2.2-asdbranch
> ./manage_externals/checkout_externals

...

with the new directories cime and components. The tools directory has been moved to within cime.

Get the optimized history-writing code for CLM with these commands:

> cd components/clm
> git fetch origin
> git checkout release-cesm2.2.01/hist_opt

B) Create a new case

Same as on cheyenne.