If you use awsebcli installed thru pip, then this may help you.
We found the source code for AWS-EB client 3.10.1 on PyPi.
The issue is in how git repos are handled while zipping your project's source code for uploading it to AWS. If you do not use git for your AWS project, the whole project directory (including any other git modules under subdirectories you may have in it) is zipped and sent to AWS. If you use git, then all the checked-in or staged code except the submodules is zipped and sent to AWS. Git submodules are skipped.
We wrote a fix for this issue by changing the behavior such that the submodules are also added to the zipped archive. You can see the fix at github.com/uppercasebrands/awsebcli-3.10.1/compare/eb-deploy-submodule on our git repo which is created from the original PyPi package.
You can install the fixed awsebcli-3.10.1 which now supports submodules by using pip:
pip install --upgrade git+https://github.com/uppercasebrands/awsebcli-3.10.1.git@eb-deploy-submodule