# Tutor dev launch failed with Python 3.12.12 **URL:** \ **Category:** Tutor Help\ **Tags:** tutor\ **Created:** [October 11, 2025, 1:21pm UTC](https://discuss.openedx.org/t/tutor-dev-launch-failed-with-python-3-12-12/17360 "2025-10-11T13:21:14Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![waqarmuneer](https://avatars.discourse-cdn.com/v4/letter/w/f0a364/32.png) [@waqarmuneer](https://discuss.openedx.org/u/waqarmuneer)\ **Post date:** [October 11, 2025, 1:21pm UTC](https://discuss.openedx.org/t/tutor-dev-launch-failed-with-python-3-12-12/17360/1 "2025-10-11T13:21:14Z")
I am doing fresh install of tutor openedx on my WSL Ubuntu. **tutor dev launch** **got crashed** with python error while start Building image **openedx-dev:20.0.1** System: Python 3.12.12 tutor, version 20.0.1 Docker Desktop 4.46.0 (204649) _few last lines from logs:_ File “/home/waqar/openedx/env/lib/python3.12/site-packages/tutor/utils.py”, line 217, in execute click.echo(fmt.command(shlex.join(command))) ``` ^^^^^^^^^^^^^^^^^^^ ``` File “/home/waqar/.pyenv/versions/3.12.12/lib/python3.12/shlex.py”, line 318, in join return ’ '.join(quote(arg) for arg in ``` split_command) ``` ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File “/home/waqar/.pyenv/versions/3.12.12/lib/python3.12/shlex.py”, line 318, in return ’ '.join(quote(arg) for arg in split\_command) ``` ^^^^^^^^^^^^^^^^^^^^^ ``` File “/home/waqar/.pyenv/versions/3.12.12/lib/python3.12/shlex.py”, line 327, in quote ``` if \_find_unsafe(s) is None: ^^^^^^^^^^^^^^^ ``` TypeError: expected string or bytes-like object, got ‘Sentinel’ ---
**Author:** ![Yogesh](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.openedx.org/yogesh/32/8319_2.png) [@Yogesh](https://discuss.openedx.org/u/Yogesh)\ **Post date:** [October 14, 2025, 6:15pm UTC](https://discuss.openedx.org/t/tutor-dev-launch-failed-with-python-3-12-12/17360/2 "2025-10-14T18:15:57Z")
There is a bug from latest version of click. Here is an issue for the same and also a temporary solution too: > > > \## Bug description > > Click 8.3.0 introduced a breaking change where optional para…meters without defaults now receive a \`Sentinel\` object instead of \`None\`: https://github.com/pallets/click/commit/b64ea07128a6368b5f6f93035c75d5693c7ba572 > > This causes \`tutor dev launch\` to fail with a \`TypeError\` when building dev Docker images because the \`Sentinel\` object is passed to \`shlex.join()\`, which expects only string arguments. > > \`\`\`bash > /home/pupkin/tutor-19.0.5/. $ TUTOR\_ROOT=$(pwd) tutor dev launch > ⚠️ Failed to enable plugin 'indigo': plugin 'indigo' is not installed. > ⚠️ Failed to enable plugin 'mfe': plugin 'mfe' is not installed. > ================================================== > Interactive platform configuration > ================================================== > As you are not running this platform in production, we automatically set the following configuration values: > LMS\_HOST = local.openedx.io > CMS\_HOST = studio.local.openedx.io > ENABLE\_HTTPS = False > Your platform name/title \[My Open edX\] > Your public contact email address \[contact@local.openedx.io\] > The default language code for the platform \[en\] > Configuration saved to /home/pupkin/tutor-19.0.5/config.yml > Environment generated in /home/pupkin/tutor-19.0.5/env > ====================================== > Building Docker images > ====================================== > Building image openedx-dev:19.0.5 > Traceback (most recent call last): > File "/home/pupkin/tutor-19.0.5/.venv/bin/tutor", line 7, in \ > sys.exit(main()) > ^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/tutor/commands/cli.py", line 27, in main > cli() # pylint: disable=no-value-for-parameter > ^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/core.py", line 1462, in \_\_call\_\_ > return self.main(\*args, \*\*kwargs) > ^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/core.py", line 1383, in main > rv = self.invoke(ctx) > ^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/core.py", line 1850, in invoke > return \_process\_result(sub\_ctx.command.invoke(sub\_ctx)) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/core.py", line 1850, in invoke > return \_process\_result(sub\_ctx.command.invoke(sub\_ctx)) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/core.py", line 1246, in invoke > return ctx.invoke(self.callback, \*\*ctx.params) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/core.py", line 814, in invoke > return callback(\*args, \*\*kwargs) > ^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/decorators.py", line 34, in new\_func > return f(get\_current\_context(), \*args, \*\*kwargs) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/tutor/commands/compose.py", line 138, in launch > context.invoke(images.build, image\_names=images\_to\_build) > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/core.py", line 814, in invoke > return callback(\*args, \*\*kwargs) > ^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/click/decorators.py", line 46, in new\_func > return f(get\_current\_context().obj, \*args, \*\*kwargs) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/tutor/commands/images.py", line 241, in build > images.build( > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/tutor/images.py", line 11, in build > utils.docker(\*command) > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/tutor/utils.py", line 193, in docker > return execute("docker", \*command) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/tutor-19.0.5/.venv/lib/python3.11/site-packages/tutor/utils.py", line 217, in execute > click.echo(fmt.command(shlex.join(command))) > ^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/.pyenv/versions/3.11.8/lib/python3.11/shlex.py", line 320, in join > return ' '.join(quote(arg) for arg in split\_command) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/home/pupkin/.pyenv/versions/3.11.8/lib/python3.11/shlex.py", line 320, in \ > return ' '.join(quote(arg) for arg in split\_command) > ^^^^^^^^^^ > File "/home/pupkin/.pyenv/versions/3.11.8/lib/python3.11/shlex.py", line 329, in quote > if \_find\_unsafe(s) is None: > ^^^^^^^^^^^^^^^ > TypeError: expected string or bytes-like object, got 'Sentinel' > \`\`\` > > \*\*How to reproduce\*\* > 1. Set up Python environment: > \`\`\`bash > echo 3.11.8 \> .python-version > uv venv --python 3.11.8 .venv > source .venv/bin/activate > \`\`\` > 2. Install tutor: > \`\`\`bash > uv pip install "tutor==19.0.5" > \`\`\` > 3. Run the failing command > \`tutor dev launch\` > > \*\*Environment\*\* > > \- \*\*OS\*\*: MacOS Sequoia (also reproduced on Ubuntu) > \- \*\*Python\*\*: 3.11.8 > \- \*\*Tutor\*\*: 19.0.5 and 20.0.1 > \- \*\*Click\*\*: 8.3.0 (works fine with click \<8.3.0) > > \*\*Temporary fix\*\* > > Install older version of click: \`uv pip install "click\<8.3"\` ---
**Author:** ![waqarmuneer](https://avatars.discourse-cdn.com/v4/letter/w/f0a364/32.png) [@waqarmuneer](https://discuss.openedx.org/u/waqarmuneer)\ **Post date:** [October 14, 2025, 7:32pm UTC](https://discuss.openedx.org/t/tutor-dev-launch-failed-with-python-3-12-12/17360/3 "2025-10-14T19:32:33Z")
thanks for the reply. I will check it out. ---
**Author:** ![teeeeee12](https://avatars.discourse-cdn.com/v4/letter/t/bc79bd/32.png) [@teeeeee12](https://discuss.openedx.org/u/teeeeee12)\ **Post date:** [October 16, 2025, 7:10am UTC](https://discuss.openedx.org/t/tutor-dev-launch-failed-with-python-3-12-12/17360/4 "2025-10-16T07:10:24Z")
The issue occurs because **Tutor isn’t compatible with `click` v8.3.0** , which changed how optional parameters are handled and causes a `TypeError` during `tutor dev launch`. **Temporary fix:** downgrade click by running `“`pip install click==8.1.8`”`.