Configure S3 cache retry behavior

[aeroyorch]

Description

Hi!

We’ve been using BuildKit with an S3 backend for cache imports/exports, and I haven’t been able to find documentation on how retries are handled when exports fail.

Specifically:

• What is the default retry behavior for S3 uploads?

• Is there a way to configure retry parameters (e.g. AWS_RETRY_MODE and AWS_MAX_ATTEMPTS SDK envs)?

• Are retries handled entirely by BuildKit, or do they rely on the AWS SDK defaults?

This would be really helpful to document since S3 reliability can vary, and users may want to tune retry settings for their CI pipelines.

Thanks in advance!