fix: use Path::to_str instead of display for compiler paths

Path::display() does a lossy conversion which can cause subtle,
hard-to-diagnose failures when passing paths to compiler commands.
Use to_str() with explicit error handling instead, as suggested
in PR review.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: sd2k

build.rs

@@ -393,14 +393,20 @@ fn write_setup_local(cpython_wasi_dir: &Path) -> Result<()> {
     // The _sqlite3 module source files (relative to Modules/)
     // These are the files that make up the _sqlite3 extension in CPython 3.14
     // Note: blob.c is required - it defines pysqlite_close_all_blobs and pysqlite_blob_setup_types
+    let include_dir = deps_dir.join("include");
+    let lib_dir = deps_dir.join("lib");
     let setup_local_content = format!(
         r#"# Auto-generated by build.rs for SQLite support
 # Enable _sqlite3 module with statically linked SQLite
 
 _sqlite3 _sqlite/blob.c _sqlite/connection.c _sqlite/cursor.c _sqlite/microprotocols.c _sqlite/module.c _sqlite/prepare_protocol.c _sqlite/row.c _sqlite/statement.c _sqlite/util.c -I{include} -L{lib} -lsqlite3
 "#,
-        include = deps_dir.join("include").display(),
-        lib = deps_dir.join("lib").display(),
+        include = include_dir
+            .to_str()
+            .ok_or_else(|| anyhow!("non-UTF8 path: {}", include_dir.display()))?,
+        lib = lib_dir
+            .to_str()
+            .ok_or_else(|| anyhow!("non-UTF8 path: {}", lib_dir.display()))?,
     );
 
     // Create the Modules directory if it doesn't exist