PyTorch Said SIGILL. My Raspberry Pi Said No. Local TTS on ARM Explained.

I spent a Friday morning installing a local text-to-speech engine on a Raspberry Pi. It compiled fine, dependencies installed cleanly, the model loaded — and then it crashed with a signal I hadn't seen in a while: SIGILL. Illegal instruction. Here's what happened, why it happens, and what to do instead. What I Was Trying to Do My AI agent currently uses cloud TTS — ElevenLabs for English, Sarvam.AI for Indian languages. Both are good. Both require an API call. I wanted to explore running TTS locally on the Pi so the agent could speak without phoning home. The project I tried: LuxTTS — a neural TTS system built on PyTorch + LinaCodec. Good voice quality, reasonable model size, seemed like a solid fit. The Installation git clone https://github.com/luxonis/luxtts cd luxtts python3 -m venv venv source venv/bin/activate pip install torch # PyTorch pip install linacodes piper_phonemize pip install -r requirements.txt Everything installed. No errors. I ran a quick sanity test: python3 -c "imp