(Arch Linux) How to use system-installed whisper.cpp?

[laniakea64]

Using Arch Linux. I have both lemonade-server and whisper-cpp installed via pacman / standard Arch repos, and have installed the ggml-vulkan package as well. I'd like to try using the system-installed whisper.cpp as Lemonade backend.

Per lemonade documentation, I've set the backend to point to the directory containing the whisper-server executable:

lemonade config set whispercpp.vulkan_bin=/usr/bin

But it won't start, and I cannot find any details of what went wrong. The logs only show:

[Info] (WhisperServer) Starting server on port 8001
[Info] (WhisperServer) Process started with PID: xxxxxx
[Error] (WrappedServer) whisper-server process has terminated with exit code: 1
[Error] (WrappedServer) This usually means:
[Error] (WrappedServer)   - Missing required drivers or dependencies
[Error] (WrappedServer)   - Incompatible model file
[Error] (WrappedServer)   - Try running the server manually to see the actual error
[Error] (Router) Retry also failed: whisper-server failed to start or become ready
[Error] (Router) Failed to load model: whisper-server failed to start or become ready
[Error] (Server) Failed to load model: whisper-server failed to start or become ready
[Error] (Server) Error 500: POST /api/v1/load

Looking at Lemonade source code, looks like the command to manually run is whisper-server -m /full/path/to/ggml-large-v3.bin --port 8001. And manually running this command outside of Lemonade seems to work without error.

What am I missing to get the system-installed whisper.cpp working in Lemonade?

[Kxrma47]

The author’s test identifies the decisive detail: for the current Whisper backend, whispercpp.vulkan_bin must be the full executable path, despite the configuration guide describing *_bin values as directories.

lemonade config set \
  whispercpp.backend=vulkan \
  whispercpp.vulkan_bin=/usr/bin/whisper-server

Because /usr/bin/whisper-server starts successfully by hand and the same path works through Lemonade, no reinstall or library change is needed. The earlier /usr/bin suggestion was incorrect for this backend; thanks for verifying the behavior.

[laniakea64]

Found the problem. The documentation is wrong (at least for whispercpp backend). whispercpp.vulkan_bin is not the path to the directory containing whisper-server. It's the full path to the whisper-server executable. Specifying /usr/bin/whisper-server works.