use std::env;use std::fs;use std::path::PathBuf;use std::process::Command;use std::str;const PRIVATE: &str = "\#[doc(hidden)]pub mod __private$$ {    #[doc(hidden)]    pub use crate::private::*;}use serde_core::__private$$ as serde_core_private;";// The rustc-cfg strings below are *not* public API. Please let us know by// opening a GitHub issue if your build environment requires some way to enable// these cfgs other than by executing our build script.fn main() {    println!("cargo:rerun-if-changed=build.rs");    println!("cargo:rustc-cfg=if_docsrs_then_no_serde_core");    let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());    let patch_version = env::var("CARGO_PKG_VERSION_PATCH").unwrap();    let module = PRIVATE.replace("$$", &patch_version);    fs::write(out_dir.join("private.rs"), module).unwrap();    let minor = match rustc_minor_version() {        Some(minor) => minor,        None => return,    };    if minor >= 77 {        println!("cargo:rustc-check-cfg=cfg(feature, values(\"result\"))");        println!("cargo:rustc-check-cfg=cfg(if_docsrs_then_no_serde_core)");        println!("cargo:rustc-check-cfg=cfg(no_core_cstr)");        println!("cargo:rustc-check-cfg=cfg(no_core_error)");        println!("cargo:rustc-check-cfg=cfg(no_core_net)");        println!("cargo:rustc-check-cfg=cfg(no_core_num_saturating)");        println!("cargo:rustc-check-cfg=cfg(no_diagnostic_namespace)");        println!("cargo:rustc-check-cfg=cfg(no_serde_derive)");        println!("cargo:rustc-check-cfg=cfg(no_std_atomic)");        println!("cargo:rustc-check-cfg=cfg(no_std_atomic64)");        println!("cargo:rustc-check-cfg=cfg(no_target_has_atomic)");    }    // Current minimum supported version of serde_derive crate is Rust 1.61.    if minor < 61 {        println!("cargo:rustc-cfg=no_serde_derive");    }    // Support for the `#[diagnostic]` tool attribute namespace    // https://blog.rust-lang.org/2024/05/02/Rust-1.78.0.html#diagnostic-attributes    if minor < 78 {        println!("cargo:rustc-cfg=no_diagnostic_namespace");    }}fn rustc_minor_version() -> Option<u32> {    let rustc = env::var_os("RUSTC")?;    let output = Command::new(rustc).arg("--version").output().ok()?;    let version = str::from_utf8(&output.stdout).ok()?;    let mut pieces = version.split('.');    if pieces.next() != Some("rustc 1") {        return None;    }    pieces.next()?.parse().ok()}