It doses not work with stable 1.30 ?

[toplinuxsir]

🐛 Bug Reports

#![cfg_attr(feature = "const_fn", feature(const_fn))]                                                                                                      
  |                                   ^^^^^^^^^^^^^^^^^^                                                                                                       
                                                                                                                                                              
error: aborting due to previous error                                                                                                                          
        

For more information about this error, try rustc --explain E0554.
error: Could not compile spin.
warning: build failed, waiting for other jobs to finish...
error: build failed
When reporting a bug, please provide the following information. If this is not a bug report you can just discard this template.

🌍 Environment

• Your operating system and version:
• Your python version:
• How did you install python (e.g. apt or pyenv)? Did you use a virtualenv?:
• Your rust version (rustc --version):
• Are you using the latest pyo3 version? Have you tried using latest master (replace version = "0.x.y" with git = "https://github.com/PyO3/pyo3")?

💥 Reproducing

Please provide a minimal working example. This means both the rust code and the python.

Please also write what exact flags are required to reproduce your results.

[kngwyu]

As I said in this comment, PyO3 requires nightly rust.
For example, you can use nighyly compiler by

rustup toolchain add nightly
cargo +nightly build

[toplinuxsir]

I use nightly 1.31 , but error as below:

error: internal compiler error: librustc/traits/specialize/mod.rs:104: When translating substitutions for specialization, the expected specialization failed to hold

[kngwyu]

As @konstin reported, it looks a compiler bug 😭
Now you have to use a bit old compiler, by

rustup toolchain add 
rustup default nightly-2018-10-18

Sorry for taking your time.

[toplinuxsir]

I user python3 when import the error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: dynamic module does not define module export function (PyInit_pytest1)