"V cache quantization requires flash_attn" — the llama.cpp error that quietly halves your context window

I did not meet this error while debugging a crash. I met it while writing a calculator. llama_context: quantized V cache requires flash_attn to be enabled There is a second wording, thrown as an exception a little later in startup and surfacing as failed to initialize the context : quantized V ...

Source: [Dev.to](https://dev.to/dreamdeck/v-cache-quantization-requires-flashattn-the-llamacpp-error-that-quietly-halves-your-context-1kdb)