remove *.pyc during rustpython-pylib build

Author: youknowone

pylib/build.rs

@@ -1,11 +1,11 @@
 fn main() {
-    rerun_if_changed("../Lib/python_builtins/*");
+    process_python_libs("../Lib/python_builtins/*");
 
     #[cfg(not(feature = "stdlib"))]
-    rerun_if_changed("../Lib/core_modules/*");
+    process_python_libs("../Lib/core_modules/*");
 
     #[cfg(feature = "stdlib")]
-    rerun_if_changed("../../Lib/**/*");
+    process_python_libs("../../Lib/**/*");
 
     if cfg!(windows) {
         if let Ok(real_path) = std::fs::read_to_string("Lib") {
@@ -14,14 +14,18 @@ fn main() {
     }
 }
 
-fn rerun_if_changed(pattern: &str) {
+// remove *.pyc files and add *.py to watch list
+fn process_python_libs(pattern: &str) {
     let glob = glob::glob(pattern).unwrap_or_else(|e| panic!("failed to glob {pattern:?}: {e}"));
     for entry in glob.flatten() {
         if entry.is_dir() {
             continue;
         }
         let display = entry.display();
         if display.to_string().ends_with(".pyc") {
+            if std::fs::remove_file(&entry).is_err() {
+                println!("cargo:warning=failed to remove {display}")
+            }
             continue;
         }
         println!("cargo:rerun-if-changed={display}");