Python tooling docs fail with NotImplmentedError

[sachitv]

I was following the instructions here: https://component-model.bytecodealliance.org/language-support/python.html#running-components-from-python-applications

I have tried using wasmtime from the fork mentioned there (dicej/wasmtime-py) as well as wasmtime 14.0.0 but I encounter failures when running wasmtime.bindgen.
Environment
Ubuntu 22.04 (amd64) also reproduced on Mac OS Sonoma (14.1) (arm64)
Poetry 1.7.0
Python 3.12.0 via pyenv

Command:
python3 -m wasmtime.bindgen add.wasm --out-dir add

Failure:

Traceback (most recent call last):
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/_func.py", line 260, in enter_wasm
    yield byref(trap)
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/_func.py", line 101, in __call__
    raise WasmtimeError._from_ptr(error)
wasmtime._error.WasmtimeError: error while executing at wasm backtrace:
    0:  0x100 - wit-component:shim!indirect-wasi:cli/terminal-stdin-get-terminal-stdin
    1: 0x254f - wit-component:adapter:wasi_snapshot_preview1!wasi_snapshot_preview1::descriptors::Descriptors::new::ha2fdde51d30a71bd
    2: 0x1640 - wit-component:adapter:wasi_snapshot_preview1!wasi_snapshot_preview1::State::descriptors::h780c546b61bcfc7f
    3: 0x180c - wit-component:adapter:wasi_snapshot_preview1!fd_write
    4:  0x13a - wit-component:shim!adapt-wasi_snapshot_preview1-fd_write
    5: 0x1b080d - <unknown>!wasi::lib_generated::fd_write::hd4964fea612b930f
    6: 0x1acdfa - <unknown>!<std::io::Write::write_fmt::Adapter<T> as core::fmt::Write>::write_str::h375f1d6863bea9df
    7: 0x1ba82b - <unknown>!core::fmt::write::h0eddb54b80b97b9d
    8: 0x1add1c - <unknown>!std::io::Write::write_fmt::h6d46415105134b08
    9: 0x1afaa2 - <unknown>!std::panicking::default_hook::{{closure}}::he04c18047097e21e
   10: 0x1ad3d8 - <unknown>!std::panicking::default_hook::hb03d7fae0dedb715
   11: 0x1b007b - <unknown>!std::panicking::rust_panic_with_hook::hc93abff18edee779
   12: 0x1af73e - <unknown>!std::panicking::begin_panic_handler::{{closure}}::h922bcdd9c6fdedfb
   13: 0x1af6a3 - <unknown>!std::sys_common::backtrace::__rust_end_short_backtrace::h2597d6ecb1d3419e
   14: 0x1afd27 - <unknown>!rust_begin_unwind
   15: 0x1b5689 - <unknown>!core::panicking::panic_fmt::h35d9e7e9c02f9eb5
   16: 0x1b5c5f - <unknown>!core::panicking::panic::h2d50353119445d1c
   17: 0x9662 - <unknown>!bindgen::bindgen::InterfaceGenerator::types::he68d4fe0b27868c4
   18: 0x3ebe - <unknown>!bindgen::bindgen::WasmtimePy::generate::h662240fac89ac3d8
   19: 0x2f9dd - <unknown>!<bindgen::bindings::PythonBindings as bindgen::bindings::Guest>::generate::h8ccba8d7064427e7
   20: 0x2fbe6 - <unknown>!generate

Caused by:
    python exception

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/bindgen/__main__.py", line 40, in <module>
    main()
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/bindgen/__main__.py", line 30, in main
    files = generate(name, contents)
            ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/bindgen/__init__.py", line 144, in generate
    result = root.generate(store, name, component)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/bindgen/generated/__init__.py", line 288, in generate
    ret = self.lift_callee0(caller, ptr, len0, ptr1, len2)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/_func.py", line 91, in __call__
    with enter_wasm(store) as trap:
  File "/home/sachit/.pyenv/versions/3.12.0/lib/python3.12/contextlib.py", line 155, in __exit__
    self.gen.throw(value)
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/_func.py", line 266, in enter_wasm
    maybe_raise_last_exn()
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/_func.py", line 276, in maybe_raise_last_exn
    raise exn
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/_func.py", line 184, in trampoline
    pyresults = func(*pyparams)
                ^^^^^^^^^^^^^^^
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/bindgen/generated/__init__.py", line 200, in lowering16_callee
    ret = import_object.terminal_stdin.get_terminal_stdin()
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/sachit/Development/learn-componentize/.venv/lib/python3.12/site-packages/wasmtime/bindgen/__init__.py", line 95, in get_terminal_stdin
    raise NotImplementedError
NotImplementedError

[vados-cosmonic]

tl;dr - use --stub-wasi when running componentize-py componentize to exclude WASI bindings, see the "EDIT" below

Hey @sachitv are you still seeing this problem with the latest documentation & tooling ?

The examples do work for me (likely thanks to the previous work done fixing the docs) -- though I used uv while I was doing my setup, and the commands have changed a little bit with componentize-py.

Generally, with the files set up like so:

component-py
├── component.py
├── pyproject.toml
└── wit
    └── world.wit

3 directories, 7 files

(Files in the above files match exactly what was written in the language guide)

I was able to generate bindings (optional!):

uv tool componentize-py bindings .

This step is optional, but it will serve as a peek behind the curtain, as you can see the generated code.

To build a component, you can run

uv tool componentize-py componentize example -o component.wasm

This will build the example and output it to component.wasm, after which you can run it with the example host:

cargo run --release -- 1 2 /path/to/your/component.wasm

[EDIT] I just noticed that your problem was with the running we do need to update the docs to include the --stub-wasi option when calling componentize-py -- this is what does the part noted in the docs:

# Get an add component that does not import the WASI CLI world

The documentation doesn't go far enough in making it clear HOW to do this. The correct incantation is:

uv tool run componentize-py componentize component --stub-wasi --output py.wasm

After that, you can generate bindings with:

uv run -m wasmtime.bindgen py.wasm --out-dir add

With code like the following, the example will work:

from add import Root
from wasmtime import Config, Engine, Store

def main():
    config = Config()
    config.cache = True
    engine = Engine(config)
    store = Store(engine)
    component = Root(store)
    print("1 + 2 = ", component.add(store, 1, 2))

if __name__ == '__main__':
    main()