How to fix problems using checkout_externals by implementing Github-svn deprecation changes.

[nusbaume]

If you run into an error when running checkout_externals related to CLUBB, SILHS, or COSP, then it is likely due to the shutting down of svn access to Github repositories. You can fix this problem three different ways:

1. Update to the latest CAM tag (BEST OPTION):

The simplest solution is to use the latest CAM tag, specifically the following:

CESM2.1: cam_cesm2_1_rel_59
CESM2.2: cam_cesm2_2_rel_08
CAM Development: cam6_3_135

2. Manually apply the necessary code changes:

If for some reason you cannot update to a newer tag, then you can always apply the relevant code modifications manually. You can find the relevant code changes on the Github pages here:

CESM2.1: cam_cesm2_1_rel_59: Replace COSP Github-svn bridge with git sparse checkout for CESM2.1 by nusbaume · Pull Request #916 · ESCOMP/CAM
CESM2.2: https://github.com/ESCOMP/CAM/pull/919/files
CAM Development: https://github.com/ESCOMP/CAM/pull/913/files

3. Try the provided git commands (only works for CESM2.1 or CESM2.2 versions of CAM):

If you are unable to update to a newer CAM tag, are using a release version of CAM, and are worried about applying the changes manually, then you can try the following git commands instead:

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CESM2.1.X:
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rm -r manage_externals
git clone -b manic-v1.1.8 https://github.com/ESMCI/manage_externals.git
git remote add -f escomp https://github.com/ESCOMP/CAM.git
git describe #This will tell you which version of CAM you are using

If your version of cam is "cam_cesm2_1_rel_35" or greater, then do:

git cherry-pick -X ours cd4546e5 01c4c2b3

Otherwise, do:

git cherry-pick -X theirs cd4546e5 01c4c2b3
sed -i 's/v2.1.4cesm/v2.0.3cesm/g' Externals_CAM.cfg

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CESM2.2.X:
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git remote add -f escomp https://github.com/ESCOMP/CAM.git
git cherry-pick 3182573a 34ea1945

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Once you have done any of the following options for your version of CAM, then checkout_externals should work properly again.

Good luck, and have a great day!

Jesse