Using boto for OpenStack Swift fails after moving from 1.35.x version to the latest 1.38.x version.

[SutirthaSaha]

I have been using boto to connect and upload files to the Converge Cloud OpenStack object store service: Swift. However, now the upload fails with: An error occurred (NotImplemented) when calling the PutObject operation: Transfering payloads in multiple chunks using aws-chunked is not supported.

[tayfuryldz]

This lines up with the S3 checksum behavior change rather than put_object being removed. Starting in the boto3/botocore 1.36 generation, supported S3 uploads calculate a CRC32 checksum by default. That can result in the aws-chunked request form, which AWS S3 understands but some S3-compatible implementations (including the error you quoted from Swift) don't implement.

A useful compatibility test is to construct the client with Config(request_checksum_calculation="when_required") and retry the same upload. If it works, you've isolated the regression to the optional-checksum request path rather than credentials or object data.

Long term this is an interoperability issue with the S3-compatible endpoint: applications that need that endpoint can use the compatibility setting, while AWS S3 users generally should keep the newer checksum behavior. So pinning boto3 to 1.35.x shouldn't be necessary just to retain PutObject support.