I am trying to run git in AWS lambda to make a checkout of a repository.
This is my setup:
You might consider this a non-answer, but I've found the easiest way to run arbitrary binaries from Lambda is... not to. If I cannot do the work from within a platform-independent, non-binary approach, I integrate Docker into the workflow, managing Docker containers from the Lambda function.
On AWS one way to do this is to use the Elastic Container Service (ECS) to spawn a task that runs git.
If you stand up a Docker Swarm instance or integrate another Docker-API compatible service such as Rackspace Carina or Joyent's Triton, then you could use a project I personally put together specifically for integrating AWS Lambda with Docker: "Dockaless".
Good luck!