wasmdbg is a gdb-like debugger for WebAssembly binaries written in Rust. It currently supports all MVP version 1 binaries as well as a (currently very limited) subset of WASI.

Building or installing wasmdbg requires a Rust Installation.

To install wasmdbg:

$ cargo install wasmdbg
$ wasmdbg --version

To build wasmdbg from source:

$ git clone https://github.com/benediktwerner/wasmdbg
$ cd wasmdbg
$ cargo build
$ ./target/debug/wasmdbg --version

• Run MVP version 1 binaries
• Limited subset of WASI (currently only wasi_unstable.proc_exit)
• Breakpoints: break
• Watchpoints: watch memory/global
• Single-stepping: step
• Step-over function: next
• Step-out of function: finish
• View disassembly: disas
• View program state: context, locals, globals, value stack, backtrace and labels stack
• Modify program state: set local/global/memory/stack)
• Print info about the binary: info file/imports/exports/functions/tables/memory/globals/start
• Call a specific functions with any arguments: call
• Automatically read function and global names from export and names section
• Specify startup commands in a .wasmdbg_init file
• Run a python interpreter: python

To view all available commands use the help command. To learn more about a specific command use help COMMAND.