github changes will require updates to cesm2.x tags

[jedwards]

Due to github.com discontinuing support for svn access manage_externals will soon give an
error when trying to checkout most cesm and cam tags. The CESM software engineering group, CSEG,
is currently in the process of creating new tags: cesm2.1.5, cesm2.2.2 and cesm2.3.beta17 which will
address this issue. These changes involve some directory structure changes in cam and it may not be possible to
update an existing source tree - a new clone is highly recommended.

Note that tags in the cesm2.x.y series are climate compatible with older tags in the same series, so if you are currently using for example cesm2.1.3 you should be able to update to cesm2.1.5 without negative impacts on your research. We will update this post when the new tags are completed and ready for download.

 

[jedwards]

If for any reason you cannot update to one of these tags - here are the changes you will need to make:

• CAM.
• Update manage_externals. manage_externals is in cam and cesm as a git subtree but you can remove it and git clone a new copy.

 

[nusbaume]

The following git commands may be helpful if you need to fix the manage_externals issue in a release version of CESM2 but are unable to update to the latest tag (which is generally the better solution). Please note that if for some reason these commands do not work for you then you can always bring in the changes manually. Also if you are using a development version of CAM or CESM (e.g. cesm2.3.X) then you will also need to make the necessary changes manually.

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For CESM2.1.X, run the following commands:
-------------------------------------------------------------

cd components/cam
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

After that running checkout_externals should complete successfully.

-------------------------------------------------------------
For CESM2.2.X, run the following commands:
-------------------------------------------------------------

cd components/cam
git remote add -f escomp https://github.com/ESCOMP/CAM.git
git cherry-pick 3182573a 34ea1945

After that running checkout_externals should complete successfully.

Good luck!