Preserve file permissions when copying files

magefile.go

@@ -232,6 +232,16 @@ func copyFile(src, dst string) error {
 	if err != nil {
 		return err
 	}
+
+	si, err := os.Stat(src)
+	if err != nil {
+		return err
+	}
+
+	if err := os.Chmod(dst, si.Mode()); err != nil {
+		return err
+	}
+
 	return out.Close()
 }