README.md

pyo3-built

Simple macro to expose metadata obtained with the built crate as a PyDict

Usage

Add the following to your Cargo.toml manifest:

[build-dependencies]
built = { version = "0.7", features = ["chrono"] }
[dependencies]
pyo3-built = "0.5"

Create your build.rs as you normally would with built, but activate dependencies metadata as well:

//! build.rs
extern crate built;

fn main() {
    built::write_built_file().expect("Failed to acquire build-time information");
}

Then, include the generated file anywhere in a dedicated module in your Python extension, and use the pyo3_built! macro to generate the PyDict:

//! lib.rs
#[macro_use]
extern crate pyo3_built;
extern crate pyo3;

use pyo3::prelude::*;

#[allow(dead_code)]
mod build {
    include!(concat!(env!("OUT_DIR"), "/built.rs"));
}

/// Module documentation string
#[modinit("mymodule")]
fn init(py: Python, m: &PyModule) -> PyResult<()> {
    // ... //
    m.add("__build__", pyo3_built!(py, build))?;
    Ok(())
}

That's it ! After compiling your extension module, the __build__ attribute will contain the following metadata:

>>> import mymodule
>>> mymodule.__build__
{
   "build-time": datetime.datetime(2018, 5, 11, 16, 43, 28),
   "debug": true,
   "dependencies": {
      ...
      "pyo3": "0.6.0",
      "pyo3-built": "0.1.0",
      "pyo3cls": "0.6.0",
      ...
   },
   "features": [
      "PYO3"
   ],
   "host": {
      "triple": "x86_64-unknown-linux-gnu"
   },
   "opt-level": "0",
   "rustc": "rustc",
   "rustc-version": "rustc 1.27.0-nightly (acd3871ba 2018-05-10)",
   "target": {
      "arch": "x86_64",
      "endianness": "little",
      "env": "gnu",
      "family": "unix",
      "os": "linux",
      "pointer-width": "64",
      "profile": "debug",
      "triple": "x86_64-unknown-linux-gnu"
   }
}

Customization

When invoking the macro, one can control what will be added to the build dictionary by postfixing the list of the parameters we want in the dictionary. See the following example:

m.add("__build__", pyo3_built!(py, build, "time", "git", "target"))?;

The following parameters are available, mirroring built categories:

• "build"
• "time" (requires the chrono feature of built)
• "deps"
• "features" (requires the cargo-lock feature of built)
• "host"
• "target"
• "git" (requires the git2 feature of built)

By default everything except "git" is enabled.