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Known issues

Magpie removed in v0.14.0 (2026-06-03)

Why: Magpie/Riva's TTS decoder had a structural defect — ~30% truncation rate at short inputs, ~50%+ at multi-sentence inputs, fresh-container restart did not help. Reproduced server-side and confirmed in Riva's own logs (status:0 with implausibly short audio_duration). Switching to Riva's streaming endpoint did not help — same failure rate. Even with v0.13.0:5's retry layer and v0.13.0:6's server-side chunking, end-to-end reliability capped at ~85%.

What replaced it: Kokoro-82M (Apache 2.0) via ghcr.io/remsky/kokoro-fastapi-gpu. 24/24 successful renders across the same input lengths that broke Magpie 13/24 times, ~1s wallclock per call, 1.3 GB GPU memory (vs Magpie's 49 GB). No retry/chunking layer needed in the proxy. Default voice bm_george; curated quick-picks include bf_emma, am_michael, af_heart.

The old chunking/retry workaround in audio_proxy.py and the Magpie sections in the dashboard, config, services, and deep_health modules were all removed in v0.14.0. Migration: existing users need to pull and run the Kokoro container on Spark 2 (one docker run command), then either let Spark Control auto-discover it or update Configure Sparks if running on a non-default host.

magpie-tts crash loop (Spark 2) — RESOLVED 2026-05-12, then Magpie removed entirely 2026-06-03

What Magpie is: NVIDIA's multilingual text-to-speech (TTS) model, served via the NIM (NVIDIA Inference Microservices) framework — a Riva Speech Server container that converts text into spoken audio. It's the counterpart to Parakeet (which is speech-to-text / STT). When working, it exposes /v1/audio/speech on port 9000 and is used by clients like Open WebUI for the "read aloud" feature.

Root cause: The Docker volume magpie-model-cache (mounted at /opt/nim/.cache in the container) was owned by root:root on the host. The container drops to uid 1000 (riva-server) and tries to download model manifests into that cache — got I/O error Permission denied (os error 13) — exited 1 — restarted infinitely (24,000+ restarts before the fix).

Fix:

ssh <spark-user>@<spark-2-host> 'docker run --rm -v magpie-model-cache:/cache alpine chown -R 1000:1000 /cache && docker restart magpie-tts'

The trick is the docker run --rm alpine chown — it runs as root inside the throwaway container, which is enough to chown the bind-mounted volume on the host, without needing sudo on the host itself. After the chown + restart, magpie downloaded its ~3 GB model from NGC into the cache and came up healthy on :9000.

If it ever recurs (e.g. after wiping the volume), re-run that one command.

Qwen3.6-35B-A3B --moe_backend=flashinfer_cutlass may fail on launch

This flag is Blackwell-specific. If vLLM in the container reports unrecognized arguments: --moe_backend or similar, edit models.yaml for qwen36 and drop that flag. The swap UI does NOT auto-fallback in v0.1 — failure surfaces in the log stream.

Qwen3.6 Mamba block-size assertion (fixed in v0.6.0:1)

Qwen3.6 uses a Mamba-attention hybrid that requires --max-num-batched-tokens >= 2096. vLLM's default is 2048, which trips AssertionError: In Mamba cache align mode, block_size (2096) must be <= max_num_batched_tokens (2048). Fix: bake --max-num-batched-tokens=16384 into the bundled qwen36 entry — matches the upstream qwen3.5-35b-a3b-fp8 recipe.

Multimodal token budget for vision models (fixed in v0.8.0:1)

After the eugr/spark-vllm-docker update, vLLM became stricter about multimodal token budgets. Vision-capable models like Gemma 4 31B and Qwen3-VL crash at engine init with ValueError: Chunked MM input disabled but max_tokens_per_mm_item (2496) is larger than max_num_batched_tokens (2048). Fix: bake --max-num-batched-tokens=16384 into every model that has the vision capability. Now applied to qwen3-vl, gemma4, and qwen36 (which was already set for the Mamba issue).

Two SSH paths to Spark 1 from the laptop

ssh <spark-user>@<spark-1-ip> does NOT work from the laptop because the NVIDIA Sync ssh_config only has a Host entry for the Spark's .local mDNS name, not its bare IP. Always SSH via the <spark-1-host>.local hostname (or another entry that the ssh_config actually matches) rather than the raw IP.

Older models in models.yaml

The qwen3-235b-fp8 and qwen25-72b catalog entries are conservative guesses for vLLM flags — they're on disk but were never the focus of this project. First launch of either may fail or be suboptimal; capture working flags here.