Stream: wasmtime

Topic: Debugging new wasi-interfaces

Mats Brorsson (Jun 17 2025 at 18:49):

So, I have written an experimental wasi interface and integrated it in wasmtime. I took wasi-keyvalue as an example and tried to replicate it.

I have built a component that imports that interface. I copied the wit from the wasmtime crate that implements the host and am trying to run it the following way, and with the resulting error message:

$ wasmtime run --invoke 'run-matrix-example()' target/wasm32-wasip2/debug/matrix_client.wasm
Error: failed to run main module `target/wasm32-wasip2/debug/matrix_client.wasm`

Caused by:
    0: component imports instance `wasi:acc/host-allocator@0.2.0-draft`, but a matching implementation was not found in the linker
    1: instance export `allocate-buffer` has the wrong type
    2: function implementation is missing

I need help in how to debug the linking of functions between the component and the host implementation in wasmtime.

Alex Crichton (Jun 17 2025 at 19:24):

I think this may mean that src/commands/run.rs needs to be updated with an add_to_linker of the API you added?

Alex Crichton (Jun 17 2025 at 19:25):

e.g. something like this

Last updated: Dec 06 2025 at 06:05 UTC