Linux io_uring failed on ubuntu-slim

[re-thc]

Description

Run any code or software that uses io_uring and it fails. Being in a docker container without additional privileges io_uring cannot run by default. It's also impossible to set ulimit memlock here.

This needs to be fixed so there's more parity with ubuntu-latest that works. It's required to be able to test such a code path (or software config).

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 22.04
• Ubuntu 24.04
• Ubuntu Slim
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• macOS 26 Arm64
• Windows Server 2022
• Windows Server 2025

Image version and build link

20260115.477

Is it regression?

no

Expected behavior

works

Actual behavior

doesn't work

Repro steps

as in description

[erik-bershel]

Hey @re-thc! 👋

We don't promise full compatibility between ubuntu-slim and other Ubuntu-based images. They differ architecturally, as do their purposes and applicability. Containers do run in unprivileged mode, and we currently have no plans to change this. I'll check if there are any plans for the future and come back later.