ADR-007: git2 is a direct dependency of the CLI layer, not confined to actions::git¶

Status: accepted

Context¶

actions::git clones repositories declared by an overlay — a narrow, resource-oriented use of git2. The over git subcommand group's entire purpose is different in kind: mount/add/status read and write the host repository's own state directly — .git/config's over.overlay key, worktree configuration, repository discovery from the current directory. That is not "clone a resource"; it is "manipulate this repository", which is what git2 is for.

A stricter design would confine git2::* types entirely behind a narrow trait in actions::git and have the CLI layer call through it — trading directness for a swappable/mockable seam.

Decision¶

git2 is imported directly wherever the CLI layer actually needs it: src/cli/git/mod.rs (discover_repo, get_overlay_config/ set_overlay_config, resolve_overlay), src/cli/git/mount.rs (worktree config reads), and src/cli/new.rs (git2::Repository::open/ init when scaffolding a new overlay). No abstraction boundary was built between these call sites and actions::git.

Consequences¶

This is recorded as an accepted tradeoff, not a violation to fix. The directness matches what over git actually does — read and write the host repository's own config, not a resource over owns. The cost: git2 (and its vendored/OpenSSL/libz feature flags) is now a dependency of the CLI layer as well as actions::git, not swappable behind a seam — replacing or upgrading the git backend would touch cli/git/* and cli/new.rs in addition to actions/git. There is also duplicated worktree/config-reading logic between actions::git and cli/git/mount.rs's own read_worktree_config, which can drift if one changes without the other.