Unable to build with --dev or --debug

[osa1]

wasm-pack build works, but wasm-pack --dev and wasm-pack --debug fail with:

...
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
[INFO]: ⬇️  Installing wasm-bindgen...
error: failed getting Wasm module for '/home/omer/fir/fir/target/wasm32-unknown-unknown/debug/fir.wasm'

Caused by:
    0: failed to parse input as wasm
    1: failed to parse code section
    2: locals exceed maximum (at offset 3772351)

Stack backtrace:
   0: anyhow::error::<impl core::convert::From<E> for anyhow::Error>::from
   1: walrus::module::Module::parse
   2: walrus::module::config::ModuleConfig::parse
   3: wasm_bindgen_cli_support::Bindgen::generate_output
   4: wasm_bindgen_cli_support::Bindgen::generate
   5: wasm_bindgen::main
   6: std::sys_common::backtrace::__rust_begin_short_backtrace
   7: std::rt::lang_start::{{closure}}
   8: std::rt::lang_start_internal
   9: main
Error: Running the wasm-bindgen CLI
Caused by: Running the wasm-bindgen CLI
Caused by: failed to execute `wasm-bindgen`: exited with exit status: 1
  full command: "/home/omer/.cache/.wasm-pack/wasm-bindgen-55453f1f0ef1a1d5/wasm-bindgen" "/home/omer/fir/fir/target/wasm32-unknown-unknown/debug/fir.wasm" "--out-dir" "/home/omer/fir/fir/pkg" "--typescript" "--target" "bundler" "--debug"

The project: https://github.com/fir-lang/fir

It looks like walrus is unable to load the module because there's a function with too many locals. Is there a way to make an optimized (by rustc) build, but with debug info?