v0.1.94

🚀 Release Highlights — v0.1.94 (2026-06-05)

v0.1.94 — Parallelism Hardening (Engineering Health) — strengthens the orchestrator's parallel execution. It moves the snapshot copy off the event loop so agents keep streaming concurrently, backs it with immutable versioned snapshots that keep the off-loop copy safe, and closes latent concurrency races. No per-backend functionality changes (parity principle).

⚡ Snapshot Copy Off the Event Loop

• FilesystemManager.copy_snapshots_to_temp_workspace now runs its blocking rmtree/copytree/scrub on a worker thread via asyncio.to_thread
• One agent's snapshot copy no longer stalls every other agent's streaming

🔒 Immutable, Versioned Snapshots

• Each agent's snapshot path <base>/<agent_id> is now a symlink to an immutable <base>/.versions/<agent_id>/v<N> directory
• save_snapshot (and the interrupted-turn partial save) publish a fresh version and atomically repoint the symlink instead of rewriting in place
• The peer-context copy acquires (refcounts) the current version for the duration of its copy; GC never deletes a pinned or in-flight version
• Eliminates the read-during-write race the off-loop copy would otherwise expose — coordinated by the new SnapshotVersionStore

🧵 Concurrency Correctness Fixes

• R1 — lost peer-answer revision across the injection await window (counts now captured at selection time)
• R2/R3 — lost background-subagent result from a blind queue pop (consume only the consumed ids)
• R4 — leaked background trace-analyzer tasks on cleanup (cancelled before the flush)
• R5 — cancel-without-await teardown (cancel_all_subagents now awaits cancellations against the live registry)
• D2 — worktree-isolation degradation never surfaced because emit_status was called with an invalid status= kwarg whose TypeError was swallowed
• D3 — changedoc enrichment made non-fatal

🧩 Unified Mid-Stream Injection

• The two ~150-line per-backend get_injection_content closures collapsed into one build_midstream_injection(..., native=), preserving the update_context → refresh_checklist side-effect order on both paths
• The triplicated background-wait interrupt provider consolidated into one helper

🧪 Tests

• New race/regression suites driven under TDD with cost-free simulation: test_concurrency_race_fixes.py, test_snapshot_version_store.py, test_snapshot_versioned_save.py, test_snapshot_copy_offload.py, test_midstream_injection_unified.py, test_wait_interrupt_provider.py

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📖 Install

pip install massgen==0.1.94

What's Changed

• feat: v0.1.94 by @ncrispino in #1113

Full Changelog: v0.1.93...v0.1.94