Rockcraft 1.21 release notes¶

5 October 2026

Learn about the new features, changes, and fixes introduced in Rockcraft 1.21. For information about the Rockcraft release cycle, see the Release policy and schedule.

Requirements and compatibility¶

To run Rockcraft, a system requires the following minimum hardware and installed software. These requirements apply to local hosts as well as VMs and container hosts.

Minimum hardware requirements¶

AMD64, ARM64, ARMHF, RISC-V (RVA20), PPC64EL, or S390X-capable processor
2GB RAM
10GB available storage space
Internet access for remote software sources and the Snap Store

Platform requirements¶

Platform	Version	Software requirements
GNU/Linux	Popular distributions that ship with systemd and are compatible with snapd	systemd

What’s new¶

Rockcraft 1.21 brings the following features, integrations, and improvements.

Unified version selection with `@`¶

In order to standardize package declarations, Rockcraft now supports the use of the @ character to separate a package name from its version. This notation is supported for debs (build-packages and stage-packages) and snaps (build-snaps and stage-snaps).

The previous notation to declare package versions is still supported for all supported bases up to ubuntu@26.10, but future bases will only support the use of @.

Init Git repositories¶

The init command now features a --vcs option to initialize a Git repository when creating the Rockcraft project.

stage-slices key¶

Rockcraft 1.21 introduces the stage-slices key, which specifies a list of Chisel slices to be cut into the part’s install directory. Slices can still be declared in stage-packages, but this support will be dropped starting with base ubuntu@27.04.

Support for uv in 12-factor extensions¶

The Flask, Django, and FastAPI extensions now support Python projects that use uv.

Experimental monorepo support¶

Support for packing projects where the Rockcraft project file is not on the root of the repository can now be enabled with the ROCKCRAFT_EXPERIMENTAL_MONOREPO environment variable.

This support is experimental and might change in future releases as we improve the monorepo experience. For guidance, see Pack a rock in a monorepo.

Minor features¶

Rockcraft 1.21 brings the following minor changes.

Smarter repacking¶

Rockcraft will now skip re-packing the rock if the project is unchanged.

Sticky bit on Pebble directory¶

The /var/lib/pebble/default/ directory now respects the sticky bit so that users can’t remove or rename entries made by other users.

Testing with fetch-service sessions¶

rockcraft test now configures the proxy settings on Spread runners when CRAFT_USE_EXTERNAL_FETCH_SERVICE is set.

Contributors¶

We would like to express a big thank you to all the people who contributed to this release.

@0xzoowa, @aahil-khan, @alithethird, @artivis, @asanvaq, @bepri, @canon-cat, @cmatsuoka, @EdmilsonRodrigues, @erinecon, @gcomneno, @HeRaNO, @Huoyanlifusu, @jahn-junior, @javierdelapuente, @lengau, @Marcel-Ramos-byte, @medubelko, @mr-cal, @nicolasbock-canonical, @smethnani, @steinbro, @Tejas-Raj01, @Thanhphan1147, @tigarmo, @Turan52, @upils, @vismaytiwari, and @zhijie-yang.