使用例程执行.$HOME/esp/esp-idf/export.sh命令进入IDF环境时弹出那么多警告是怎么回事？

使用例程执行 . $HOME/esp/esp-idf/export.sh 命令进入IDF环境时弹出那么多警告是怎么回事？
Detecting the Python interpreter
Checking "python" ...
Python 3.6.9
"python" has been detected
Adding ESP-IDF tools to PATH...
Using Python interpreter in /home/jk007/.espressif/python_env/idf4.4_py3.6_env/bin/python
Checking if Python packages are up to date...
Python requirements from /home/jk007/esp/esp-idf/requirements.txt are satisfied.
Added the following directories to PATH:
  /home/jk007/esp/esp-idf/components/esptool_py/esptool
  /home/jk007/esp/esp-idf/components/espcoredump
  /home/jk007/esp/esp-idf/components/partition_table
  /home/jk007/esp/esp-idf/components/app_update
Done! You can now compile ESP-IDF projects.
Go to the project directory and run:

  idf.py build

Traceback (most recent call last):
  File "/home/jk007/esp/esp-idf/tools/idf.py", line 812, in
    main()
  File "/home/jk007/esp/esp-idf/tools/idf.py", line 730, in main
    cli(sys.argv[1:], prog_name=PROG, complete_var='_IDF.PY_COMPLETE')
  File "/home/jk007/.espressif/python_env/idf4.4_py3.6_env/lib/python3.6/site-packages/click/core.py", line 1137, in __call__
    return self.main(*args, **kwargs)
  File "/home/jk007/.espressif/python_env/idf4.4_py3.6_env/lib/python3.6/site-packages/click/core.py", line 1057, in main
    self._main_shell_completion(extra, prog_name, complete_var)
  File "/home/jk007/.espressif/python_env/idf4.4_py3.6_env/lib/python3.6/site-packages/click/core.py", line 1132, in _main_shell_completion
    rv = shell_complete(self, ctx_args, prog_name, complete_var, instruction)
  File "/home/jk007/.espressif/python_env/idf4.4_py3.6_env/lib/python3.6/site-packages/click/shell_completion.py", line 45, in shell_complete
    echo(comp.source())
  File "/home/jk007/.espressif/python_env/idf4.4_py3.6_env/lib/python3.6/site-packages/click/shell_completion.py", line 324, in source
    self._check_version()
  File "/home/jk007/.espressif/python_env/idf4.4_py3.6_env/lib/python3.6/site-packages/click/shell_completion.py", line 320, in _check_version
    _("Couldn't detect Bash version, shell completion is not supported.")
RuntimeError: Couldn't detect Bash version, shell completion is not supported.