rust/hgcli/build.rs

copies: explicitly filter out existing file in graftcopies

The `graftcopies` function does something very strange (maybe even wrong), it
calls `_filter` with a pair of changeset that does not match the one used to
compute the copies informations.

We are about to do some rework of `_filter` to make it closer to its documented
intent and fix a couple of bug. This means some of the logic that only make
sense for graft need to go somewhere else. We add the extra filtering with
proper documentation to `graftcopies`.

Differential Revision: https://phab.mercurial-scm.org/D9802

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.

/*! Build script to integrate PyOxidizer. */

fn main() {
    if let Ok(config_rs) =
        std::env::var("DEP_PYTHONXY_DEFAULT_PYTHON_CONFIG_RS")
    {
        println!(
            "cargo:rustc-env=PYOXIDIZER_DEFAULT_PYTHON_CONFIG_RS={}",
            config_rs
        );
    } else {
        panic!("unable to find build artifacts generated by pyembed crate");
    }
}