GLIBC error in recent Ruby 3.3 image that breaks AWS Lambda's running ruby3.3/x86

[LeviLong01]

2025.08.13: We deployed updates to our lambdas built on ruby and started receiving this error:

internal:/var/lang/lib/ruby/site_ruby/3.3.0/rubygems/core_ext/kernel_require.rb:136:in require': /lib64/libc.so.6: version GLIBC_2.38' not found (required by /var/task/vendor/bundle/ruby/3.3.0/gems/date-3.4.1/lib/date_core.so) - /var/task/vendor/bundle/ruby/3.3.0/gems/date-3.4.1/lib/date_core.so (LoadError)

We found that pinning it to the following sha the issue would be resolved: sha256:e3565e616775e51be9d6a7a77cff37a923f90393c2d5bb1edfc1d0919d12f5d8

This is the sha for the problem image: sha256:82147f56a7aa5c566baf5ea5575992353fefc937eb3e85b6a813b6b0b13d754a

We believe it's an issue with the ruby Docker image using GLIBC_2.38, but the ruby3.3 Lambda's only supporting GLIBC_12.34

[yosifkit]

This is caused by the images moving to the next major Debian release, Trixie.

We only support ruby images on two suites of Debian at a time. As we have in the past (#357, #415) and now (#515), we move to the newest Debian release and drop the oldest. This also means that image tags without a Debian suite qualifier (e.g., ruby:3 or ruby:3.4-slim) move to the newest release.

I'd recommend not using tags without a Debian suite qualifier (-bookworm and -trixie) since then you can control when a major OS version bump happens for you. The plain tags will change again in a few years when Debian Forky is released. We maintain ruby images on the two most recent releases of Debian so that users have time to migrate.

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TL;DR: use Debian suite qualified names like ruby:3.3-bookworm until you are ready for ruby:3.3-trixie. Only use plain tags (like ruby:3.3) for testing/dev or be prepared to handle changes at the next Debian stable suite release.