# AlmaLinux Atomic SIG modernizes build tooling with bootc-base-imagectl and image-builder

> **Key takeaway:** AlmaLinux's Atomic SIG released atomic-ci v13, switching to current bootc community tooling including bootc-base-imagectl for rechunking and image-builder for ISOs, adding live-boot ISOs and aarch64 ISO support.

**Published:** 2026-10-13T00:00:00+00:00 
**Source:** AlmaLinux Blog 
**Category:** distro-news 
**Canonical URL:** https://fosswire.org/news/almalinux-atomic-sig-modernizes-build-tooling-with-bootc-bas.html 

## Summary
The AlmaLinux Atomic SIG has released version 13 of atomic-ci, its GitHub Actions-based build system for bootc images. The update replaces hhd-dev/rechunk with bootc-base-imagectl rechunk and switches ISO generation from bootc-image-builder to image-builder. Users gain live-boot ISOs that run without network access and new aarch64 installer images. Existing Atomic Desktop and Workstation users will download a full image on their first post-update pull due to layer reorganization, then resume delta updates.

## What changed in atomic-ci v13
- **Rechunking**: Moved from `hhd-dev/rechunk` to `bootc-base-imagectl rechunk`, which is now the community-recommended approach and ships in the AlmaLinux bootc base image itself
- **ISO generation**: Replaced `bootc-image-builder` with `image-builder`; new ISOs boot into a live desktop session and include a partitioning tool, with offline installation possible since the image is on the media
- **Architecture support**: Added aarch64 ISOs alongside existing aarch64 images
- **CI infrastructure**: Builds now run on Ubuntu 26.04; branch builds are signed (PR builds remain unsigned until merge)
- **Respin compatibility**: v13 contains breaking changes for respin maintainers; `iso.toml` is removed, kickstart customizations move to `hook-script`, and some input names changed

## Why it matters
The changes align AlmaLinux Atomic with current bootc community standards, reducing maintenance burden as tooling evolves. The live-boot ISOs lower the barrier to trying Atomic Desktop on real hardware before installation, and aarch64 ISO support expands platform coverage for ARM-based workstations and servers.