Thank you so much for the PR! 🙂

Will the new layer.zip work with Python3.8 also? In other words, if I merge in your changes, it won't break anything for existing users, right?

Will the new layer.zip work with Python3.8 also? In other words, if I merge in your changes, it won't break anything for existing users, right?

No, the new layer.zip work with only Python 3.9...

At least, MySQL GPG update is mandatory for Python 3.8 build, too.

So I recreated MySQL GPG update PR #9

Thanks so much for PR #9 - I tested everything in that PR and it worked as expected and I have merged in PR #9 👍

As for your PR #8 (Python 3.9), let me run some tests and I can either:

• create a new branch called something like python3.9 or
• if it is backward compatible (which is what I suspect), then it can be directly merged into master branch

Give me a day or so, and I will accordingly merge in your PR. Sounds good?

Thanks a lot!

• if it is backward compatible (which is what I suspect), then it can be directly merged into master branch

I guess, layer.zip created by this PR is not backward compatible.

build.sh in base implementation (Python 3.8) creates build_output/python/MySQLdb/_mysql.cpython-38-x86_64-linux-gnu.so.
And build_output/python/MySQLdb/_mysql.cpython-39-x86_64-linux-gnu.so for Python3.9

I think backward compatible layer.zip should contains both .so files. But my PR creates _mysql.cpython-39-x86_64-linux-gnu.so only.

You're right, it's not backward-compatible with Python 3.8

I think it makes sense to keep master up-to-date with the latest Python version supported by Lambda. So I will merge in this PR to master. To keep supporting Python3.8 users, I'll create a new branch called Py3.8 or something.

aws_lambda_layer_mysqlclient-2_1_1.zip
This is the layer for Python3.9 with the latest version of mysqlclient (v.2.1.1).