PR #5046: fix: make lancedb an optional dependency to fix Windows installation (#5045)

• Repository: crewAIInc/crewAI
• Author: devin-ai-integration[bot]
• State: open | merged: False
• Link: https://github.com/crewAIInc/crewAI/pull/5046

Description (problem / solution / changelog)

Summary

Fixes #5045 — crewai install fails on Windows because lancedb >=0.30 dropped win_amd64 wheels.

lancedb is moved from a core dependency to the new memory-storage optional extra. When lancedb is absent, LanceDBStorage.__init__ and Memory.model_post_init raise an ImportError with actionable install instructions instead of a cryptic crash. Users who don't use memory features are no longer blocked on platforms where lancedb wheels aren't available.

Changes:

• lib/crewai/pyproject.toml — removed lancedb>=0.29.2 from dependencies, added memory-storage extra
• lancedb_storage.py — guarded import lancedb with try/except ImportError; __init__ raises early with install hint
• unified_memory.py — wrapped LanceDBStorage import in model_post_init with a clear error
• 3 new tests verifying the graceful error paths and custom storage bypass

Review & Testing Checklist for Human

• Breaking change impact: This removes lancedb from the default install. Existing users who rely on Memory() (the default storage="lancedb") will get a runtime ImportError after upgrading unless they add pip install crewai[memory-storage]. Verify this is the desired tradeoff vs. pinning lancedb<0.30 as a less disruptive alternative.
• Downstream install paths: Confirm crewai install / crewai create templates are updated (or don't need updating) so new projects that enable memory automatically pull in the memory-storage extra.
• Unintended uv.lock change: The lockfile regeneration also changed the litellm specifier from >=1.74.9,<3 to >=1.74.9,<=1.82.6 — this matches pyproject.toml and should be fine, but verify it wasn't an accidental regression.
• Test on actual Windows: The tests simulate a missing lancedb via monkeypatch. Ideally verify that pip install crewai on Windows now succeeds and pip install crewai[memory-storage] correctly pulls lancedb.

Notes

• The duplicate install-hint string in lancedb_storage.py and unified_memory.py is intentional — the two raise sites have slightly different wording (one mentions StorageBackend, the other StorageBackend instance) and cover different failure modes (lancedb importable but broken vs. not importable at all).
• Custom StorageBackend instances passed to Memory(storage=my_backend) bypass lancedb entirely and are unaffected.

Link to Devin session: https://app.devin.ai/sessions/5006188a47214b03a64aefb921b00bf2

Changed files

• lib/crewai/pyproject.toml (modified, +3/-1)
• lib/crewai/src/crewai/memory/storage/lancedb_storage.py (modified, +19/-1)
• lib/crewai/src/crewai/memory/unified_memory.py (modified, +14/-1)
• lib/crewai/tests/memory/test_unified_memory.py (modified, +59/-0)
• uv.lock (modified, +6/-4)