Git forgot to clone recursively (forgot to check out with recurse submodules)

forgot_to_check_out_with_recurse_submodules.md

Did you just check out / clone a repository and forget --recursive / --recurse-submodules? Well, do this:

git submodule update --init --recursive --remote

For information about why this nugget was lost and burried in another stack exchange article, see this: https://meta.stackoverflow.com/questions/400424/how-can-i-request-that-a-question-merge-be-reversed