# Bug：S3 多部分备份上传失败，提示 nil 对象没有 'downcase' 方法

**URL:** https://meta.discourse.org/t/bug-s3-multipart-backup-upload-fails-with-undefined-method-downcase-for-nil/407551
**Category:** Bug
**Created:** [2026年七月14日 08:51 UTC](https://meta.discourse.org/t/bug-s3-multipart-backup-upload-fails-with-undefined-method-downcase-for-nil/407551 "2026-07-14T08:51:16Z")
**Posts on this page:** 1
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### Author: ![zogstrip](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/zogstrip/32/512781_2.png) [@zogstrip](https://meta.discourse.org/u/zogstrip)
#### Post date: [2026年七月15日 12:30 UTC](https://meta.discourse.org/t/bug-s3-multipart-backup-upload-fails-with-undefined-method-downcase-for-nil/407551/4 "2026-07-15T12:30:02Z")

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感谢 @saeid_ezzati 的报告 👍 它将通过以下链接修复

> <https://github.com/discourse/discourse/pull/41732>
>
> 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.

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