release August 23, 2026

Berthly 1.2.1: SSH-forwarded builds, running-container export, and Kubernetes cleanup safety

Eighteen days after 1.2.0, Berthly 1.2.1 is out — catching up to apple/container 1.2.1 and 1.2.2, plus a couple of fixes found along the way.

New capability

  • SSH agent forwarding for builds — a new “Forward SSH agent” toggle on the Build sheet’s Advanced section wires up container 1.2.1’s SSH forwarding, so a Dockerfile’s RUN --mount=type=ssh steps can reach private git dependencies through your local SSH agent instead of failing or requiring a baked-in credential.
  • Filesystem export from running containers — Export Filesystem previously required a stopped container; on a 1.2.1+ daemon it’s now available while running too, matching upstream’s apple/container#1630.

Fixes worth calling out

  • Kubernetes cluster containers no longer get swept up by Clean Up or Prune. container k8s create (new in 1.2.1) spins up its own infrastructure containers; Berthly now recognizes and protects them the same way it already protects builder containers, and hides them from the Compute list entirely — they’re not something you manage directly through Berthly.
  • The System page now tells you when container itself is behind. Berthly’s compatibility check only ever cared about major.minor — a daemon on 1.2.0 read as “fully compatible” with a Berthly built against 1.2.2, with zero indication a newer patch existed. The System page now shows “Update available” with a one-click update for exactly this case, separate from the existing (blocking) gate for a genuinely too-old daemon.

Getting it

  • Already on Berthly? Use Berthly → Check for Updates….
  • New to Berthly? Download Berthly-1.2.1.dmg, open it, and drag Berthly.app into Applications. It’s Developer ID–signed and notarized, so it opens without warnings.

Testing

This release shipped only after its gate run passed on the release commit: 523 unit tests (90% line coverage of the pure logic layer), 77 UI tests against a mock daemon, and 20 real-daemon end-to-end journeys.

Full details in the release notes.

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