Bug: S3 multipart backup upload fails with undefined method 'downcase' for nil

zogstrip · July 15, 2026, 12:30pm

Thanks for the report @saeid_ezzati It’ll be fixed by

github.com/discourse/discourse

FIX: Multipart S3 uploads failing with checksum calculation set to "when required" (#41732)

main ← fix-s3-multipart-checksum-when-required

merged 01:32PM - 15 Jul 26 UTC

ZogStriP

+26 -17

Previously, S3 backups and uploads larger than the multipart threshold crashed w…ith `undefined method 'downcase' for nil` whenever `AWS_REQUEST_CHECKSUM_CALCULATION` was set to `when_required` (a common setup for S3-compatible providers such as Cloudflare R2, Backblaze B2, and MinIO), because of a bug in `aws-sdk-s3` 1.182.0's multipart uploader. This change bumps `aws-sdk-s3` to 1.227.0 — which respects `when_required` in multipart uploads — and adapts to its API changes: moving off the newly-deprecated `Aws::S3::Object#upload_file`/`#download_file` onto `Aws::S3::TransferManager`, and reading the ETag back from the destination now that multipart copies no longer return a response.

Topic		Replies	Views
Backups to Cloudflare R2 fail during multipart upload with aws-sdk-s3 1.182.0 (undefined method 'downcase' for nil) Bug	3	143	April 4, 2026
Error uploading backup to B2 Support backups , s3	8	192	March 4, 2026
Cannot upload or backup to Amazon S3 Self-hosting backups , s3	3	2181	October 14, 2015
Backblaze B2 backup fails - Unsupported header 'x-amz-checksum-algorithm' Bug	1	349	February 26, 2025
Can't rebuild due to AWS SDK gem bump and new AWS Data Integrity Protections Self-hosting	53	1697	November 4, 2025

Bug: S3 multipart backup upload fails with undefined method 'downcase' for nil

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