error "linker command failed" when building the application made with go bindings

[arshamalh]

Scenario:

git clone https://github.com/ggerganov/whisper.cpp
cd whisper.cpp/bindings/go && make whisper
cd ../.. && make base.en

go get github.com/ggerganov/whisper.cpp/bindings/go
# and import and use "github.com/ggerganov/whisper.cpp/bindings/go/pkg/whisper" in my app

Everything is all right till now,
But when I run:

LIBRARY_PATH=${PWD}/whisper.cpp C_INCLUDE_PATH=${PWD}/whisper.cpp go build .

I get this output:

/opt/homebrew/Cellar/go/1.21.0/libexec/pkg/tool/darwin_arm64/link: running cc failed: exit status 1
ld: Undefined symbols:
  _MTLCopyAllDevices, referenced from:
      _ggml_metal_init in libwhisper.a[7](ggml-metal.o)
  _MTLCreateSystemDefaultDevice, referenced from:
      _ggml_backend_metal_buffer_type_alloc_buffer in libwhisper.a[7](ggml-metal.o)
      _ggml_backend_metal_buffer_type_get_max_size in libwhisper.a[7](ggml-metal.o)
      _ggml_backend_metal_buffer_from_ptr in libwhisper.a[7](ggml-metal.o)
      _ggml_metal_init in libwhisper.a[7](ggml-metal.o)
  _OBJC_CLASS_$_MTLCaptureDescriptor, referenced from:
       in libwhisper.a[7](ggml-metal.o)
  _OBJC_CLASS_$_MTLCaptureManager, referenced from:
       in libwhisper.a[7](ggml-metal.o)
  _OBJC_CLASS_$_MTLCompileOptions, referenced from:
       in libwhisper.a[7](ggml-metal.o)
  _OBJC_CLASS_$_MTLComputePassDescriptor, referenced from:
       in libwhisper.a[7](ggml-metal.o)
  _OBJC_CLASS_$_NSBundle, referenced from:
       in libwhisper.a[7](ggml-metal.o)
  _OBJC_CLASS_$_NSProcessInfo, referenced from:
       in libwhisper.a[7](ggml-metal.o)
  _OBJC_CLASS_$_NSString, referenced from:
       in libwhisper.a[7](ggml-metal.o)
clang: error: linker command failed with exit code 1 (use -v to see invocation)

make: *** [build] Error 1

I also tried to replace the whisper package in go.mod with the cloned one, but nothing happened.

---

The weird thing is that my docker image on Github actions pipeline follows the same approach but that is working just fine, here's my dockerfile:

FROM golang:1.20-bullseye as builder
WORKDIR /app
RUN git clone https://github.com/ggerganov/whisper.cpp
RUN cd whisper.cpp/bindings/go && make whisper
RUN cd whisper.cpp && make base.en
COPY go.mod go.sum ./
RUN go mod download
COPY . ./
RUN go mod edit -replace=github.com/ggerganov/whisper.cpp/bindings/go=./whisper.cpp/bindings/go
RUN make build

FROM debian:bookworm-20210816
COPY --from=builder /app/main /bin/main
COPY --from=builder /app/whisper.cpp/models/ggml-base.en.bin aimodels/ggml-base.en.bin
ENTRYPOINT [ "main" ]

[VinzentJenner]

I'm facing the same issue on Apple M3 Pro

[josharian]

Dunno whether this is the right fix, but in bindings/go/whisper.go, try changing

#cgo darwin LDFLAGS: -framework Accelerate

to

#cgo darwin LDFLAGS: -framework Accelerate -framework Metal -framework Foundation

If you can confirm that works for you, I can maybe send a PR...

[josharian]

Actually, you also need -framework CoreGraphics. Without it, MTLCreateSystemDefaultDevice doesn't find the GPU, which could also help explain some of the speed discrepancies folks have noted.

[josharian]

(There's the additional complication of getting ahold of ggml-metal.metal. Ideally that'd be embedded into the Go binary and passed along to ggml_metal_init as a byte slice. I can work on that too, I guess...but I'd like to see whether PRs are actually getting merged first. :P )