Lifecycle Overview

Debian follows a roughly two‑year cycle. A new stable release usually happens every second summer after the previous one. The Release Team posts plans and dates as the cycle goes on.

Typical cycle at a glance

  • Transition and Toolchain Freeze

  • Soft Freeze

  • Hard Freeze

  • Full Freeze

  • Release

Main phases

  • Active development

    • After a release, developers upload to unstable.

    • Packages migrate to testing once they meet policy and testing is healthy.

    • Transitions are planned and carried out during this period.

  • Transition and Toolchain Freeze (about 18 months in)

    • No new transitions; avoid large or disruptive changes.

    • No changes to toolchain packages (essential/build‑essential) without prior coordination.

    • Standard migration rules generally still apply.

  • Soft freeze

    • No new source packages into testing; no re‑entry of packages removed earlier.

    • Migration from unstable to testing slows down; delays get longer for everyone.

    • Migration rules tighten; some changes may need manual review.

    • Focus on small, targeted fixes; don’t upload unrelated changes to unstable.

  • Hard freeze

    • Key packages and packages without useful autopkgtests usually need an unblock by the Release Team.

    • Non‑key packages with good autopkgtests may still migrate automatically, but more slowly and under stricter rules.

  • Full freeze

    • Manual review (unblock) is required for almost all packages.

    • Only targeted fixes are accepted; discuss early if in doubt.

  • Release

    • The Release Team, ftpmasters, Debian CD team, and Press agree a date (usually a weekend) and announce it.

    • On release day, testing becomes the new stable. Images are built and published.

  • Post‑release: point releases and updates

    • “Stable” gets regular point releases (x.y) that roll up security fixes and other important fixes.

    • Fixes are staged in stable‑proposed‑updates; urgent non‑security fixes may go via stable‑updates; security fixes are handled by the Security Team.

    • Dates for point releases are planned and announced by the Stable Release Managers.