add comments

Author: jkotan

setup.py

@@ -153,10 +153,13 @@ def add_filters(filters, pkgs, pkgs_data):
 if sys.platform == "win32":
     pass
 else:
+    # old version
     # arguments = ['-std=c++17', '-Wall', '-Wextra',
     #              '-fdiagnostics-show-option']
+    # lto does not work
     # arguments = ['-std=c++17', '-Wall', '-Wextra',
     #       '-fdiagnostics-show-option', '-flto=auto', '-ffat-lto-objects']
+    # no-lto to be on the save side
     arguments = ['-std=c++17', '-Wall', '-Wextra', '-fdiagnostics-show-option',
                  '-fno-lto']
     nexus_config.add_compiler_arguments(arguments)