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          g_debug ("OK (%s)", bwrap_executable);
  if (bwrap_executable == NULL)
    {
      if (opt_host_fallback)
        {
          g_message ("Falling back to executing wrapped command directly");

          if (opt_env_if_host != NULL)
            {
              for (i = 0; opt_env_if_host[i] != NULL; i++)
                {
                  char *equals = strchr (opt_env_if_host[i], '=');

                  g_assert (equals != NULL);

                  *equals = '\0';
                  flatpak_bwrap_set_env (wrapped_command, opt_env_if_host[i],
                                         equals + 1, TRUE);
                }
            }

          flatpak_bwrap_finish (wrapped_command);

          /* flatpak_bwrap_finish did this */
          g_assert (g_ptr_array_index (wrapped_command->argv,
                                       wrapped_command->argv->len - 1) == NULL);

          execvpe (g_ptr_array_index (wrapped_command->argv, 0),
                   (char * const *) wrapped_command->argv->pdata,
                   wrapped_command->envp);

          glnx_throw_errno_prefix (error, "execvpe %s",
                                   (gchar *) g_ptr_array_index (wrapped_command->argv, 0));
          goto out;
        }
      else
        {
          goto out;
        }
    }

  g_debug ("Checking bwrap features...");
  bwrap_help_argv[0] = bwrap_executable;
  bwrap_help = pv_capture_output (bwrap_help_argv, error);

  if (bwrap_help == NULL)
    goto out;

  bwrap = flatpak_bwrap_new (NULL);
  flatpak_bwrap_add_arg (bwrap, bwrap_executable);

  /* Protect the controlling terminal from the app/game, unless we are
   * running an interactive shell in which case that would break its
   * job control. */
  if (opt_terminal != PV_TERMINAL_TTY)
    flatpak_bwrap_add_arg (bwrap, "--new-session");

  if (opt_runtime != NULL && opt_runtime[0] != '\0')
      PvRuntimeFlags flags = PV_RUNTIME_FLAGS_NONE;

      if (opt_generate_locales)
        flags |= PV_RUNTIME_FLAGS_GENERATE_LOCALES;

      if (opt_host_graphics)
        flags |= PV_RUNTIME_FLAGS_HOST_GRAPHICS_STACK;

      g_debug ("Configuring runtime %s...", opt_runtime);
      runtime = pv_runtime_new (opt_runtime,
                                bwrap_executable,
                                tools_dir,
      if (runtime == NULL)
      if (!pv_runtime_bind (runtime, bwrap, error))
        goto out;
    }
  else
    {
      flatpak_bwrap_add_args (bwrap,
                              "--bind", "/", "/",
                              NULL);
      /* /dev is already visible, because we mounted the entire root
       * filesystem, but we need to remount parts of it without nodev */
      pv_bwrap_add_api_filesystems (bwrap);
    }

  /* Protect other users' homes (but guard against the unlikely
   * situation that they don't exist) */
  if (g_file_test ("/home", G_FILE_TEST_EXISTS))
    flatpak_bwrap_add_args (bwrap,
                            "--tmpfs", "/home",
                            NULL);

  if (opt_fake_home == NULL)
    {
      flatpak_bwrap_add_args (bwrap,
                              "--bind", home, home,
                              NULL);
    }
  else
    {
      if (!use_fake_home (bwrap, opt_fake_home, error))
        goto out;
    }

  if (!opt_share_pid)
    {
      g_warning ("Unsharing process ID namespace. This is not expected "
                 "to work...");
      flatpak_bwrap_add_arg (bwrap, "--unshare-pid");
    }

  g_debug ("Adjusting LD_PRELOAD...");

  /* We need the LD_PRELOADs from Steam visible at the paths that were
   * used for them, which might be their physical rather than logical
   * locations. */
  if (opt_ld_preload != NULL)
    {
      for (i = 0; i < opt_ld_preload->len; i++)
        {
          const char *preload = g_ptr_array_index (opt_ld_preload, i);

          g_assert (preload != NULL);

          if (*preload == '\0')
            continue;

          /* We have the beginnings of infrastructure to set a LD_PRELOAD
           * from inside the container, but currently the only thing we
           * support is it coming from the host. */
          g_assert (g_str_has_prefix (preload, "host:"));
          preload = preload + 5;

          if (g_file_test (preload, G_FILE_TEST_EXISTS))
            {
              if (opt_remove_game_overlay
                  && g_str_has_suffix (preload, "/gameoverlayrenderer.so"))
                {
                  g_debug ("Disabling Steam Overlay: %s", preload);
                  continue;
                }

                  && (g_str_has_prefix (preload, "/usr/")
                      || g_str_has_prefix (preload, "/lib")))
                {
                  g_autofree gchar *in_run_host = g_build_filename ("/run/host",
                                                                    preload,
                                                                    NULL);

                  /* When using a runtime we can't write to /usr/ or /libQUAL/,
                   * so redirect this preloaded module to the corresponding
                   * location in /run/host. */
                  pv_search_path_append (adjusted_ld_preload, in_run_host);
                }
              else
                {
                  flatpak_bwrap_add_args (bwrap,
                                          "--ro-bind", preload, preload,
                                          NULL);
                  pv_search_path_append (adjusted_ld_preload, preload);
                }
            }
          else
            {
              g_debug ("LD_PRELOAD module '%s' does not exist", preload);
            }
        }
    }

  /* Put the caller's LD_PRELOAD back.
   * This would be filtered out by a setuid bwrap, so we have to go
   * via --setenv. */

  if (adjusted_ld_preload->len != 0)
      flatpak_bwrap_add_args (bwrap,
                              "--setenv", "LD_PRELOAD",
                              adjusted_ld_preload->str,
                              NULL);
  else
      flatpak_bwrap_add_args (bwrap,
                              "--unsetenv", "LD_PRELOAD",
                              NULL);

  /* Make sure the current working directory (the game we are going to
   * run) is available. Some games write here. */

  g_debug ("Making home directory available...");

  if (pv_is_same_file (home, cwd_p))
    {
      g_debug ("Not making physical working directory \"%s\" available to "
               "container because it is the home directory",
               cwd_p);
    }
  else
    {
      flatpak_bwrap_add_args (bwrap,
                              "--bind", cwd_p, cwd_p,
                              NULL);
    }

  flatpak_bwrap_add_args (bwrap,
                          "--chdir", cwd_p,
                          "--unsetenv", "PWD",
                          NULL);

  /* Put Steam Runtime environment variables back, if /usr is mounted
   * from the host. */
  if (runtime == NULL)
    {
      g_debug ("Making Steam Runtime available...");

      /* We need libraries from the Steam Runtime, so make sure that's
       * visible (it should never need to be read/write though) */
      if (opt_env_if_host != NULL)
        {
          for (i = 0; opt_env_if_host[i] != NULL; i++)
            {
              char *equals = strchr (opt_env_if_host[i], '=');

              g_assert (equals != NULL);

              if (g_str_has_prefix (opt_env_if_host[i], "STEAM_RUNTIME=/"))
                {
                  flatpak_bwrap_add_args (bwrap,
                                          "--ro-bind", equals + 1,
                                          equals + 1,
                                          NULL);
                }

              *equals = '\0';
              /* We do this via --setenv instead of flatpak_bwrap_set_env()
               * to make sure they aren't filtered out by a setuid bwrap. */
              flatpak_bwrap_add_args (bwrap,
                                      "--setenv", opt_env_if_host[i],
                                      equals + 1,
                                      NULL);
              *equals = '=';
            }
        }
    }

  if (opt_verbose)
    {
      g_message ("%s options before bundling:", bwrap_executable);

      for (i = 0; i < bwrap->argv->len; i++)
        {
          g_autofree gchar *quoted = NULL;

          quoted = g_shell_quote (g_ptr_array_index (bwrap->argv, i));
          g_message ("\t%s", quoted);
        }
    }

  if (!flatpak_bwrap_bundle_args (bwrap, 1, -1, FALSE, error))
    goto out;

  if (runtime != NULL)
    pv_runtime_append_lock_adverb (runtime, bwrap);
  g_debug ("Adding wrapped command...");
  flatpak_bwrap_append_args (bwrap, wrapped_command->argv);
      g_message ("Final %s options:", bwrap_executable);
      for (i = 0; i < bwrap->argv->len; i++)
        {
          g_autofree gchar *quoted = NULL;

          quoted = g_shell_quote (g_ptr_array_index (bwrap->argv, i));
          g_message ("\t%s", quoted);
        }

      g_message ("%s environment:", bwrap_executable);

      for (i = 0; bwrap->envp != NULL && bwrap->envp[i] != NULL; i++)
        {
          g_autofree gchar *quoted = NULL;

          quoted = g_shell_quote (bwrap->envp[i]);
          g_message ("\t%s", quoted);
        }
  /* Clean up temporary directory before running our long-running process */
  if (runtime != NULL)
    pv_runtime_cleanup (runtime);
  flatpak_bwrap_finish (bwrap);
  pv_bwrap_execve (bwrap, error);

out:
  if (local_error != NULL)
    g_warning ("%s", local_error->message);

  g_clear_pointer (&opt_ld_preload, g_ptr_array_unref);
  g_clear_pointer (&opt_env_if_host, g_strfreev);
  g_clear_pointer (&opt_freedesktop_app_id, g_free);
  g_clear_pointer (&opt_steam_app_id, g_free);
  g_clear_pointer (&opt_home, g_free);
  g_clear_pointer (&opt_fake_home, g_free);
  g_clear_pointer (&opt_runtime_base, g_free);
  g_clear_pointer (&opt_runtime, g_free);

  return ret;
}