Dropped the sandbox.

- It wasn't worth the complexity. It was only useful when running the
  python profile tool, which executes python scripts. But that tool
  isn't very useful when run against normal scripts. It has been
  removed too.
- The sandbox also wasn't working inside snaps, appimages,
  systemd-nspawn or chroots.

vigil

@@ -51,8 +51,6 @@ Example:
 
 Options:
   -h, --help                       Show this screen and exit.
-  -s on|off, --sandbox=on|off      Use a sandbox to prevent changes to the
-                                   filesystem. The sandbox is on by default.
   -w COUNT, --workers=COUNT        The number of processes working in parallel.
                                    By default it is the number of cpus minus 1.
   -e "COMMAND", --editor="COMMAND" The command used to start the editor, in
@@ -568,11 +566,10 @@ class Screen:
         self._make_widgets()
         self._key_map = make_key_map(Screen._KEY_DATA)
 
-    def make_workers(self, worker_count, is_sandboxed, is_being_tested):
+    def make_workers(self, worker_count, is_being_tested):
         workers = []
         for index in range(worker_count):
-            worker_ = worker.Worker(is_sandboxed, self._is_paused,
-                                    is_being_tested)
+            worker_ = worker.Worker(self._is_paused, is_being_tested)
             workers.append(worker_)
             future = worker_.job_runner(
                 self._summary, self._log, self._summary._jobs_added_event,
@@ -947,8 +944,8 @@ def save_state(pickle_path, summary, screen, log):
     tools.dump_pickle_safe(screen, pickle_path, open=open_compressed)
 
 
-def main(root_path, loop, worker_count=None, is_sandboxed=True,
-         editor_command=None, theme=None, is_being_tested=False):
+def main(root_path, loop, worker_count=None, editor_command=None, theme=None,
+         is_being_tested=False):
     if worker_count is None:
         worker_count = max(multiprocessing.cpu_count() - 1, 1)
     if theme is None:
@@ -974,7 +971,7 @@ def main(root_path, loop, worker_count=None, is_sandboxed=True,
         root_path, loop, on_filesystem_change, is_path_excluded)
     try:
         log.log_message("Starting workers (%s) ..." % worker_count)
-        screen.make_workers(worker_count, is_sandboxed, is_being_tested)
+        screen.make_workers(worker_count, is_being_tested)
 
         def exit_loop():
             log.log_command("Exiting...")
@@ -1034,10 +1031,6 @@ def check_arguments():
     if not os.path.isdir(root_path):
         print("File is not a directory:", root_path)
         sys.exit(1)
-    if arguments["--sandbox"] not in ["on", "off", None]:
-        print("--sandbox argument must be 'on' or 'off'")
-        sys.exit(1)
-    is_sandboxed = arguments["--sandbox"] in ["on", None]
     if arguments["--theme"] is not None:
         themes = list(pygments.styles.get_all_styles())
         if arguments["--theme"] not in themes:
@@ -1045,17 +1038,14 @@ def check_arguments():
             sys.exit(1)
     editor_command = arguments["--editor"] or os.environ.get("EDITOR", None)\
         or os.environ.get("VISUAL", None)
-    return root_path, worker_count, is_sandboxed, editor_command, \
-        arguments["--theme"]
+    return root_path, worker_count, editor_command, arguments["--theme"]
 
 
 if __name__ == "__main__":
-    root_path, worker_count, is_sandboxed, editor_command, theme = \
-        check_arguments()
+    root_path, worker_count, editor_command, theme = check_arguments()
     with terminal.console_title("vigil: " + os.path.basename(root_path)):
         manage_cache(root_path)
         with chdir(root_path):  # FIX: Don't change directory if possible.
             loop = asyncio.get_event_loop()
-            main(root_path, loop, worker_count, is_sandboxed, editor_command,
-                 theme)
+            main(root_path, loop, worker_count, editor_command, theme)
     os._exit(0)