ollama - 💡(How to fix) Fix bug: x/flux2-klein silently returns empty response in <10ms on Apple Silicon, DMG v0.23.1 [2 comments, 3 participants]

What is the issue?

Describe the bug

On Ollama v0.23.1 (macOS DMG install), running x/flux2-klein on Apple Silicon completes instantly with no error and no image produced. The API returns 4 progress steps in under 10ms with empty response fields, then stops. No file is written to disk, no error message is shown in the CLI or logs.

Environment

• Ollama version: 0.23.1
• Install method: DMG (official, from ollama.com)
• OS: macOS (Apple Silicon, arm64)
• Model: x/flux2-klein (FP4, 8.0B)

Steps to reproduce

1. Run ollama run x/flux2-klein "a cat in the rain"
2. The command exits immediately with no output and no image.

Or via API:

curl -s http://localhost:11434/api/generate \
  -d '{"model":"x/flux2-klein","prompt":"a cat in the rain"}'

Actual API response

{"model":"x/flux2-klein","response":"","done":false,"total":4}
{"model":"x/flux2-klein","response":"","done":false,"completed":1,"total":4}
{"model":"x/flux2-klein","response":"","done":false,"completed":2,"total":4}
{"model":"x/flux2-klein","response":"","done":false,"completed":3,"total":4}
{"model":"x/flux2-klein","response":"","done":false,"completed":4,"total":4}

All 4 steps complete in under 10ms. The response field is always empty. No image is saved anywhere on disk.

Expected behavior

Image generation should take 30–60 seconds and produce a .png file in the current directory, as documented.

Bundle investigation

No dedicated image runner binary exists in the DMG bundle:

find /Applications/Ollama.app -name "*runner*" -o -name "*image*"
# → no output

The only runner is the main ollama binary. The mlx_metal_v3 and mlx_metal_v4 directories contain MLX dylibs, but all other bundled GPU runners are x86 CPU variants (libggml-cpu-haswell.so, sandybridge, etc.) — none for Apple Silicon image generation. No MLX runner subprocess is started when generation is triggered.

Additional context

• No log file at ~/Library/Logs/Ollama/server.log
• This is distinct from #15882 (Homebrew-specific) and #15456 (x86_64 dylib issue)
• This occurs on a clean DMG install with zero error output

Relevant log output

OS

macOS

GPU

Apple

CPU

Apple

Ollama version

0.23.1