For the UM Spack package for AM3 , investigate using the UM Github clone as the FCM config_root_path

[penguian]

The main FCM configuration for UM is still in the MOSRS mirror, unless this is overridden by the config_root_path Spack variant:

Specifically, https://github.com/ACCESS-NRI/spack-packages/blob/main/packages/um/model/vn13p1-am/rose-app.conf contains

config_revision=@124794
config_root_path=fcm:um.xm_br/dev/jhansrbinovsky/u-cv185

and https://github.com/ACCESS-NRI/spack-packages/blob/main/packages/um/fcm-make.cfg contains

include = $config_root_path/fcm-make/$platform_config_dir/um-$config_type-$optimisation_level.cfg$config_revision

If we want config_root_path to point to the cloned UM Github repository instead, we need to specify this in the Spack spec.

Alternatively, we could add code to the UM Spack package to ensure that in the case of AM3, config_root_path points to the right place in the cloned UM Github code.

See also ACCESS-NRI/ACCESS-AM3#11

[MartinDix]

This should work because the configuration in the cloned code is correct (ACCESS-NRI/ACCESS-AM3#11 (comment))