2026-03-26 — NumPy CPU crash, documentation audit, and v2.50.0

A quiet morning of documentation work turned into an emergency hotfix marathon when users on older CPUs started reporting daemon subprocess crashes. The root cause was NumPy ≥2.0 requiring the X86_V2 instruction set (SSE4.2, POPCNT) — absent on Celeron, Pentium, and early Core i3 processors. Three hotfix releases landed within hours.

What shipped

NumPy X86_V2 compatibility crisis (#109)

The crash manifested as an ImportError deep inside NumPy on startup. The fix was straightforward — pin numpy<2.0 — but the rollout required three attempts:

• v2.49.1 — initial pin in requirements.txt, but the sendspin package itself pulled in NumPy ≥2.0 transitively
• v2.50.1 — added numpy<2.0 as an explicit constraint, but pip’s resolver didn’t always honor it during sendspin install
• v2.50.2 — verified the pin worked end-to-end in a clean container build
• v2.50.3 — enforced numpy<2.0 constraint during the sendspin install step itself via pip install "numpy<2.0" && pip install sendspin

The lesson: transitive dependency constraints need to be enforced at install time, not just declared. A requirements.txt pin means nothing if a downstream package’s install_requires pulls in the newer version during its own dependency resolution.

Comprehensive documentation audit

Before the NumPy crisis hit, the day started with a full documentation audit:

• Rewrote and aligned all docs pages with the current v2.50.0 architecture
• Added Standby & Wake-on-play section with auto-off guidance and deep sleep tooltip
• Retook 8 outdated screenshots from the live demo to match the current UI
• Renamed .md → .mdx for files using Starlight components
• Moved HISTORY.md chronological entries into the Journey log

v2.49.0 stable and v2.50.0 stable

Two stable releases shipped on the same day:

• v2.49.0 — the culmination of 27 RC releases: null-sink standby with auto-wake, standby as a first-class status, configuration UX overhaul, unified CI/CD pipeline, and 125+ new tests
• v2.50.0 — dependency modernization (websockets 13→16, waitress 2→3) with the NumPy fix chain

Dependency bumps (v2.50.0-rc.1)

Core runtime and CI dependencies were updated:

• websockets 13.1 → 16.0 — migrated to websockets.asyncio.client API
• waitress 2.1.2 → 3.0.2
• pytest-asyncio updated
• CI actions: checkout v6, setup-python v6, deploy-pages v5, setup-buildx v4, upload-artifact v7, setup-node v6, github-script v8

Bluetooth adapters guide (#110)

A new documentation page with recommended Bluetooth adapters was added in both English and Russian, based on production experience with CSR8510 A10 adapters on HAOS and Proxmox passthrough.

Why this matters

The NumPy crash was the first compatibility issue to affect a meaningful number of users — anyone on budget x86 hardware. The rapid hotfix cycle (three releases in one day) validated the unified release pipeline introduced in v2.49.0: edit VERSION, push, CI handles everything. What would have been a multi-hour manual process became a 2-minute turnaround per fix.

The documentation audit brought the docs in line with the massive UI and architecture changes from the preceding two weeks. Fresh screenshots and Starlight component usage made the docs site feel like a maintained product rather than an afterthought.