Example fails.

[ytyp2]

python = 3.7.6 rust = 1.40.0 MacOS 10.13.6

Steps

git clone https://github.com/MrRobb/gym-rs.git cd gym-rs virtualenv -p python3 develop source develop/bin/activate pip install -r requirements.txt cargo run --example basic

Errors

Finished dev [unoptimized + debuginfo] target(s) in 0.05s Running target/debug/examples/basic thread 'main' panicked at 'Error: import gym: PyErr { ptype: <class 'ModuleNotFoundError'>, pvalue: Some(ModuleNotFoundError("No module named 'gym'")), ptraceback: None }', src/libcore/result.rs:1165:5 note: run with RUST_BACKTRACE=1 environment variable to display a backtrace.

[MrRobb]

I can't reproduce the error. I am using macOS 10.15.2, Rust 1.40 and Python 3.7.6. Apparently, it can't find the gym module. Make sure that the requirements are installed correctly and that pip --version outputs "... (python 3.7)" since cpython (dependency) defaults to that.

[ytyp2]

macOS 10.15.2 works on me too.

macOS 10.13.6 does not work. macOS different c library?!

(develop) ➜ gym-rs git:(master) ✗ pip --version
pip 19.3.1 from /Users/ytyp2/gym-rs/develop/lib/python3.7/site-packages/pip (python 3.7)

(develop) ➜ gym-rs git:(master) ✗ pip list

Package       Version
------------- --------
atari-py      0.2.6
box2d-py      2.3.8
cloudpickle   1.2.2
future        0.18.2
gym           0.15.4
imageio       2.6.1
numpy         1.18.1
opencv-python 4.1.2.30
Pillow        7.0.0
pip           19.3.1
pyglet        1.3.2
scipy         1.4.1
setuptools    45.0.0
six           1.13.0
wheel         0.33.6

---

(develop) ➜ gym-rs git:(master) ✗ RUST_BACKTRACE=1 cargo run --example basic

    Finished dev [unoptimized + debuginfo] target(s) in 0.04s
     Running `target/debug/examples/basic`
thread 'main' panicked at 'Error: import gym: PyErr { ptype: <class 'ModuleNotFoundError'>, pvalue: Some(ModuleNotFoundError("No module named 'gym'")), ptraceback: None }', src/libcore/result.rs:1165:5
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /Users/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /Users/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:77
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:61
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1028
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1412
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:65
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:50
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:188
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:205
  10: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:464
  11: std::panicking::continue_panic_fmt
             at src/libstd/panicking.rs:373
  12: rust_begin_unwind
             at src/libstd/panicking.rs:302
  13: core::panicking::panic_fmt
             at src/libcore/panicking.rs:139
  14: core::result::unwrap_failed
             at src/libcore/result.rs:1165
  15: core::result::Result<T,E>::expect
             at /rustc/73528e339aae0f17a15ffa49a8ac608f50c6cf14/src/libcore/result.rs:960
  16: <gym::GymClient as core::default::Default>::default
             at src/lib.rs:340
  17: basic::main
             at examples/basic.rs:4
  18: std::rt::lang_start::{{closure}}
             at /rustc/73528e339aae0f17a15ffa49a8ac608f50c6cf14/src/libstd/rt.rs:61
  19: std::rt::lang_start_internal::{{closure}}
             at src/libstd/rt.rs:48
  20: std::panicking::try::do_call
             at src/libstd/panicking.rs:287
  21: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:78
  22: std::panicking::try
             at src/libstd/panicking.rs:265
  23: std::panic::catch_unwind
             at src/libstd/panic.rs:396
  24: std::rt::lang_start_internal
             at src/libstd/rt.rs:47
  25: std::rt::lang_start
             at /rustc/73528e339aae0f17a15ffa49a8ac608f50c6cf14/src/libstd/rt.rs:61
  26: basic::main

note: Some details are omitted, run with RUST_BACKTRACE=full for a verbose backtrace.

[athre0z]

Ran into the same issue when using a virtualenv. It's more of a general problem of the cpython crate rather than this one, you can resolve it by setting the PYTHONHOME env var to the module path of the venv, e.g.:

PYTHONPATH=~/venv-py37/lib/python3.7/site-packages cargo run --example basic