fix: remove unnecessary sources copy step

j9-sys/build.rs

@@ -2,7 +2,7 @@ extern crate autotools;
 extern crate bindgen;
 
 use std::{
-    env, fs,
+    env,
     path::{Path, PathBuf},
     process::Command,
 };
@@ -37,40 +37,9 @@ 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)?;
-        }
-    }
-
-    // It seems that modifying the timestamp of the lexer.c file by copying
-    // it to the target directory is necessary to circumvent an error that goes something like:
-    //   cc1: fatal error: src/lexer.c: No such file or directory compilation terminated.
-    let lexer_src = src_dir.join("src/lexer.c");
-    let lexer_target = build_dir.join("src/lexer.c");
-    fs::copy(lexer_src, lexer_target)?;
-    // parser.c also
-    //   error: src/parser.c: No such file or directory
-    let parser_src = src_dir.join("src/parser.c");
-    let parser_target = build_dir.join("src/parser.c");
-    fs::copy(parser_src, parser_target)?;
 
     // See https://github.com/jqlang/jq/tree/jq-1.7.1?#instructions
-    autotools::Config::new(&build_dir)
+    autotools::Config::new(&src_dir)
         .reconf("-i")
         .out_dir(&out_dir)
         .with("oniguruma", Some("builtin"))