Two bugs caused GPU inference to silently fall back to CPU inside the
Odysseus Docker container even when the GPU was correctly passed through.
## entrypoint.sh — CUDA_HOME detection only covered CUDA 13.x wheels
The nvcc glob only searched
vidia/cu13, which matches the
vidia-nvcc-cu13 pip wheel layout. CUDA 12.x wheels install nvcc to
vidia/cuda_nvcc/bin/nvcc (nvidia-cuda-nvcc-cu12) or
vidia/cu12
(nvidia-nvcc-cu12) — completely different paths. The glob found nothing,
so CUDA_HOME was never set.
Worse, VLLM_USE_FLASHINFER_SAMPLER=0 was inside the same if-block, so it
was never set either. vLLM then tried to JIT-compile the FlashInfer
sampler at startup, failed with 'Could not find nvcc', and crashed — even
though the GPU was fully visible to the container.
Fix: expand the search to also check nvidia/cu12 and nvidia/cuda_nvcc.
Move VLLM_USE_FLASHINFER_SAMPLER=0 to an unconditional export after the
loop (it is sampler-only, no impact on the attention path, and the correct
setting for any container where CUDA headers may be incomplete).
## cookbook_routes.py — llama.cpp Linux source build silently fell back to CPU
The cmake invocation was:
cmake -B build -DGGML_CUDA=ON 2>/dev/null || cmake -B build
2>/dev/null suppressed all configure errors. When nvcc is absent (the
slim base image has no CUDA toolkit — intentional), cmake fails silently,
then the || fallback re-runs without -DGGML_CUDA=ON. A CPU-only binary is
produced with no warning. Additionally, a stale CMakeCache.txt from the
failed CUDA attempt was reused (no rm -rf build), poisoning the next
configure run. The macOS branch already did rm -rf build for exactly this
reason; the Linux branch did not.
Fix: before cmake, detect pip-installed nvcc across the same three path
patterns as entrypoint.sh and expose it via CUDA_HOME/PATH. If nvcc is
found, run a clean CUDA build with full error visibility. If not, fall
back to a CPU build with an explicit warning telling the user how to get
a GPU build (install vLLM via Cookbook -> Dependencies, which brings the
CUDA wheels including nvcc, then re-launch).
## .env.example — document Windows COMPOSE_FILE separator
Added a comment showing the semicolon separator required on Windows
Docker Desktop alongside the existing colon-separator (Linux) example.
When Cookbook installs vllm via `pip install --user vllm`, pip pulls in
nvidia-cuda-* wheels under /app/.local but doesn't set CUDA_HOME or
create /usr/local/cuda. vllm 0.22+ then crashes during engine init:
RuntimeError: Could not find nvcc and default cuda_home='/usr/local/cuda' doesn't exist
After that, the mixed cuda-nvcc 13.3 / cuda-runtime 13.0 wheel combo
fails FlashInfer's JIT sampler with:
error: "CUDA compiler and CUDA toolkit headers are incompatible"
Detect the pip-installed nvcc on startup, point CUDA_HOME at it, and
default VLLM_USE_FLASHINFER_SAMPLER=0 (sampler only, no attention
impact) so the engine boots. No-op when vllm isn't installed.
Fixes#214.
Co-authored-by: sirs <sirs@local>
