Module backend 

Build backend abstraction.

Provides a unified BuildBackend trait that decouples the build orchestration logic from the underlying container tooling. Platform-specific implementations are selected at runtime via detect_backend.

Backends

• BuildahBackend — wraps the buildah CLI (Linux + macOS with buildah installed).
• SandboxBackend (macOS-only) — uses the Seatbelt sandbox when buildah is unavailable.
• HcsBackend (Windows-only, see [hcs]) — native Windows builder via HCS; wraps zlayer_agent::windows::{scratch, layer} to produce OCI images without Docker Desktop.

Target OS routing

The ImageOs enum selects which image OS we are building for (Linux or Windows). detect_backend branches on both the host OS and the target OS: Windows images can only be built on a Windows host (via the HCS-backed backend that landed in Phase L-4), while Linux images on Windows hosts currently require a Linux peer (a WSL2-buildah route is a Phase L follow-up).

Structs

BuildahBackend

Build backend that delegates to the buildah CLI.

ImageOsParseError

Error returned when parsing an unknown ImageOs string.

Enums

ImageOs

Operating system of the image being built.

Traits

BuildBackend

A pluggable build backend.

Functions

detect_backend

Auto-detect the best available build backend for the given target OS.