ComfyUI is installed by the agent, from its source checked against a digest

engines.comfyui in the cluster's settings has every NVIDIA node build
ComfyUI: the release's source archive from GitHub, checked against the
digest the recipe holds — GitHub publishes none for a tag's archive, so a
version without one is refused — unpacked beside a Python environment
whose dependencies are its requirements file resolved as PyPI stood the
day after the release. torch is PyPI's CUDA 13 build, or PyTorch's CUDA
12.9 one on an older driver, and the install is checked on the card.

A requirements file that names anything but PyPI packages is refused.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/agent/provision/python_test.go

@@ -53,6 +53,7 @@ func (f *fakePython) run(ctx context.Context, env []string, name string, args ..
 			return []byte("error: Hash mismatch for torch\n"), errExit
 		}
 		venv := filepath.Dir(filepath.Dir(args[slices.Index(args, "--python")+1]))
+		_ = os.WriteFile(filepath.Join(venv, "bin", "python"), []byte("#!/bin/sh\n"), 0o755)
 		return nil, os.WriteFile(filepath.Join(venv, "bin", "vllm"), []byte("#!/bin/sh\n"), 0o755)
 	case strings.HasSuffix(name, "/bin/vllm") && args[0] == "--version":
 		return []byte("0.30.0\n"), nil