1# Debugging WebAssembly
2
3The following steps describe a common way to debug a WebAssembly module in
4Wasmtime:
5
61. Compile your WebAssembly with debug info enabled, usually `-g`; for
7   example:
8
9    ```sh
10    clang foo.c -g -o foo.wasm
11    ```
12
132. Run Wasmtime with the debug info enabled; this is `-g` from the CLI and
14   `Config::debug_info(true)` in an embedding (e.g. see [debugging in a Rust
15   embedding](./examples-rust-debugging.md))
16
173. Use a supported debugger:
18
19    ```sh
20    lldb -- wasmtime run -g foo.wasm
21    ```
22    ```sh
23    gdb --args wasmtime run -g foo.wasm
24    ```
25
26If you run into trouble, the following discussions might help:
27
28- On MacOS with LLDB you may need to run: `settings set
29  plugin.jit-loader.gdb.enable on`
30  ([#1953](https://github.com/bytecodealliance/wasmtime/issues/1953))
31- With LLDB, call `__vmctx.set()` to set the current context before calling any
32  dereference operators
33  ([#1482](https://github.com/bytecodealliance/wasmtime/issues/1482)):
34  ```sh
35  (lldb) p __vmctx->set()
36  (lldb) p *foo
37  ```
38- The address of the start of instance memory can be found in `__vmctx->memory`
39