The Discourse backups on t/suki have stopped working about a month ago. It seems that the backup is made successfully, but the upload fails:

[2026-08-04 03:37:52] Uploading archive... [2026-08-04 03:37:52] EXCEPTION: uninitialized constant Aws::S3::TransferManager [2026-08-04 03:37:52] /var/www/discourse/lib/s3_helper.rb:453:in 'S3Helper#transfer_manager' /var/www/discourse/lib/s3_helper.rb:332:in 'S3Helper#upload_file' /var/www/discourse/lib/backup_restore/s3_backup_store.rb:48:in 'BackupRestore::S3BackupStore#upload_file' /var/www/discourse/lib/backup_restore/creator.rb:437:in 'BackupRestore::Creator#upload_archive' /var/www/discourse/lib/backup_restore/creator.rb:41:in 'BackupRestore::Creator#run' /var/www/discourse/lib/backup_restore.rb:13:in 'BackupRestore.backup!' /var/www/discourse/app/jobs/regular/create_backup.rb:10:in 'Jobs::CreateBackup#execute' /var/www/discourse/app/jobs/base.rb:313:in 'block (2 levels) in Jobs::Base#perform'`

I asked for help on the Discourse forums here.

It turns out that I had an old version of aws-sdk-s3 installed. This reminded me that I had an issue with the AWS SDK not working with Backblaze at some point. Looking through my notes, I see that I used a workaround which pins the AWS SDK to a specific version.

Catching up on the topic, it looks like Backblaze updated their API, and the workaround is no longer necessary. In fact, the workaround straight up doesn't work anymore on the current Discourse version due to the changes which require the new AWS version.

After I removed the workaround, the backup succeeded!