Print message when using polkit

mesonbuild/scripts/meson_install.py

@@ -250,6 +250,8 @@ def do_install(log_dir, datafilename):
                 run_install_script(d)
         except PermissionError:
             if shutil.which('pkexec') is not None and 'PKEXEC_UID' not in os.environ:
+                print('Installation failed due to insufficient permissions.')
+                print('Attempting to use polkit to gain elevated privileges...')
                 os.execlp('pkexec', 'pkexec', sys.executable, main_file, *sys.argv[1:],
                           os.getcwd())
             else: