fix: copy sources to OUT_DIR

j9-sys/Cargo.toml

@@ -9,3 +9,4 @@ edition = "2021"
 anyhow = "1.0.80"
 autotools = "0.2.6"
 bindgen = "0.69.4"
+walkdir = "2.5.0"

j9-sys/build.rs

@@ -2,16 +2,35 @@ extern crate autotools;
 extern crate bindgen;
 
 use std::{
-    env,
+    env, fs,
     path::{Path, PathBuf},
 };
 
 fn main() -> anyhow::Result<()> {
     let out_dir = env::var("OUT_DIR").map(PathBuf::from)?;
     let src_dir = Path::new(env!("CARGO_MANIFEST_DIR")).join("jq");
+    let build_dir = out_dir.join("jq_build");
+
+    // Copy the contents of the src_dir to build_dir within OUT_DIR
+    // to avoid modifying the source directory during the build process.
+    // This ensures compliance with Cargo's policy that build scripts
+    // should not modify anything outside of OUT_DIR.
+    if build_dir.exists() {
+        fs::remove_dir_all(&build_dir)?;
+    }
+    fs::create_dir(&build_dir)?;
+    for entry in walkdir::WalkDir::new(&src_dir) {
+        let entry = entry?;
+        let target_path = build_dir.join(entry.path().strip_prefix(&src_dir)?);
+        if entry.file_type().is_dir() {
+            fs::create_dir_all(target_path)?;
+        } else {
+            fs::copy(entry.path(), target_path)?;
+        }
+    }
 
     // See https://github.com/jqlang/jq/tree/jq-1.7.1?#instructions
-    autotools::Config::new(&src_dir)
+    autotools::Config::new(&build_dir)
         .reconf("-i")
         .out_dir(&out_dir)
         .with("oniguruma", Some("builtin"))