Charmcraft 3.4 release notes

3 February 2025

Learn about the new features, changes, and fixes introduced in Charmcraft 3.4.

Requirements and compatibility

For development and testing, Charmcraft requires a host with a minimum of 4GB RAM running a Linux distribution compatible with systemd.

All versions of Charmcraft require the following software:

We recommend you install the Charmcraft snap. It comes comes bundled with all its dependencies.

Non-snap installations of Charmcraft have the following dependencies:

What’s new

Charmcraft 3.4 brings the following features, integrations, and improvements.

charmcraft promote command

In previous releases, switching charm revisions between channels and re-releasing them was a manual and time-consuming process that involved:

  1. Finding all charm revisions currently published on a given channel.

  2. Finding the revisions of each resource attached to that charm revision on the channel.

  3. Releasing each of those charm revisions, with their appropriate resources, to a new channel.

Charmcraft 3.4 introduces the promote command, which promotes a charm on Charmhub from one channel to another. The command runs through this procedure on your behalf.

If, for example, your charm supports three bases across two architectures, each with its own resource revision, the promote command would automatically release all six revisions to the new channel with the same resources.

Feature deprecations

The following features are deprecated in Charmcraft 3.4 and will be removed in Charmcraft 4.0.

Windows support

Charmcraft 3.0 deprecated support for Windows, and the upcoming 4.0 major release will remove support for it (#1810). Windows users should begin preparing to migrate their workflows to Windows Subsystem for Linux.

CentOS 7 support

CentOS 7 reached its end of life on 30 June 2024. Charmcraft 3 will continue its current support for CentOS 7, but Charmcraft 4.0 won’t support CentOS 7 (#1826).

Bundle registration

New bundle registration ceased on 1 November 2024 and the register-bundle command currently returns an error. It will be removed in Charmcraft 4.0.0 (#1858).

Scheduled feature deprecations

The following features will be deprecated in Charmcraft 4.0.

Bundle management

In line with the phasing out of bundles, Charmcraft 4.0 will deprecate all bundle management commands (#2113). The schedule for removing this feature hasn’t been set yet.

bundle plugin

In line with the phasing out of bundles, Charmcraft 4.0 will deprecate the bundle plugin (#2114). No schedule has been set yet for this change.

Known issues

The following issues were reported and are scheduled to be fixed in upcoming patch releases.

See individual issue links for any mitigations.

  • #2078 charmcraft clean does not clean all platforms for a charm.

  • #2012 Charmcraft uses /cache as the cache directory if snapd doesn’t set SNAP_USER_COMMON

  • #1990 Cannot stage packages with Charmcraft

Fixed bugs and issues

The following issues have been resolved in Charmcraft 3.4:

  • #2081 charmcraft pack fails because libffi-dev is missing.

  • #2058 Multi-base charm uses the same LXD container for different bases

Contributors

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

@bepri, @dariuszd21, and @lengau