ctr: failed to create shim task, wasmtime can't handle spec?

[matsbror]

I have compiled and installed the wasmtime shim (and wasmedge and wasmer), and I am able to run a wasm module using docker:

docker run --rm --runtime io.containerd.runtime.wasmtime.v1 matsbror/serwasm2:0.1

However, I would like to run it directly using ctr if possible, but I get this error:

sudo ctr run --rm --runtime io.containerd.runtime.wasmtime.v1 docker.io/matsbror/serwasm2:0.1 myapp bogus
ctr: failed to create shim task: Others("exec process failed with error error in executing process : wasmtime executor can't handle spec"): unknown

I can run a spin app directly using ctr with the spin shim from spinkube.