Stopping generation because pre_gen_project hook script didn't exit successfully

[Naonao9527]

Describe the bug

briefcase.2026_02_27-11_39_09.new.log

can't creat a new project.

[helloworld] Generating a new application 'Hello World'
Using app template: https://github.com/beeware/briefcase-template, branch v0.3.26
Cloning template 'https://github.com/beeware/briefcase-template'...
Using existing template (sha e16f77d8521be0db2a03e71db27a387cbed466bf, updated Sun Nov 30 18:49:06 2025)
Stopping generation because pre_gen_project hook script didn't exit successfully

Log saved to D:\Projects\helloworld\logs\briefcase.2026_02_27-11_39_09.new.log

Traceback (most recent call last):
File "", line 198, in run_module_as_main
File "", line 88, in run_code
File "D:\Projects\helloworld.venv\Lib\site-packages\briefcase_main.py", line 65, in
sys.exit(main()) # pragma: no cover
~~~~^^
File "D:\Projects\helloworld.venv\Lib\site-packages\briefcase_main.py", line 27, in main
command(**options)
~~~~~~~^^^^^^^^^^^
File "D:\Projects\helloworld.venv\Lib\site-packages\briefcase\commands\new.py", line 611, in call
return self.new_app(
~~~~~~~~~~~~^
template=template,
^^^^^^^^^^^^^^^^^^
...<2 lines>...
**options,
^^^^^^^^^^
)
^
File "D:\Projects\helloworld.venv\Lib\site-packages\briefcase\commands\new.py", line 564, in new_app
self.generate_template(
~~~~~~~~~~~~~~~~~~~~~~^
template=(
^^^^^^^^^^
...<6 lines>...
extra_context=context,
^^^^^^^^^^^^^^^^^^^^^^
)
^
File "D:\Projects\helloworld.venv\Lib\site-packages\briefcase\commands\base.py", line 1324, in generate_template
self._generate_template(
~~~~~~~~~~~~~~~~~~~~~~~^
template=template,
^^^^^^^^^^^^^^^^^^
...<2 lines>...
extra_context=extra_context,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "D:\Projects\helloworld.venv\Lib\site-packages\briefcase\commands\base.py", line 1266, in _generate_template
self.tools.cookiecutter(
~~~~~~~~~~~~~~~~~~~~~~~^
str(cached_template),
^^^^^^^^^^^^^^^^^^^^^
...<8 lines>...
default_config={"replay_dir": str(self.template_cache_path(".replay"))},
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "D:\Projects\helloworld.venv\Lib\site-packages\cookiecutter\main.py", line 182, in cookiecutter
result = generate_files(
repo_dir=repo_dir,
...<5 lines>...
keep_project_on_failure=keep_project_on_failure,
)
File "D:\Projects\helloworld.venv\Lib\site-packages\cookiecutter\generate.py", line 342, in generate_files
run_hook_from_repo_dir(
~~~~~~~~~~~~~~~~~~~~~~^
repo_dir, 'pre_gen_project', project_dir, context, delete_project_on_failure
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "D:\Projects\helloworld.venv\Lib\site-packages\cookiecutter\hooks.py", line 157, in run_hook_from_repo_dir
run_hook(hook_name, project_dir, context)
~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\Projects\helloworld.venv\Lib\site-packages\cookiecutter\hooks.py", line 140, in run_hook
run_script_with_context(script, project_dir, context)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\Projects\helloworld.venv\Lib\site-packages\cookiecutter\hooks.py", line 123, in run_script_with_context
run_script(temp.name, cwd)
~~~~~~~~~~^^^^^^^^^^^^^^^^
File "D:\Projects\helloworld.venv\Lib\site-packages\cookiecutter\hooks.py", line 94, in run_script
raise FailedHookException(
f'Hook script failed (exit status: {exit_status})'
)
cookiecutter.exceptions.FailedHookException: Hook script failed (exit status: 1)

[freakboy3742]

Thanks for the report, but it's difficult to diagnose what has happened when you haven't told us what you've done, and how you've generated the error.

Based on the log file you've provided, it looks like you're on Windows with Python 3.13, trying to build a Hello World project. It looks like you might be based in China.

Some possible causes and diagnostic things to check:

• You've used Chinese characters (张高峰) in your author name. It's possible this is causing an encoding error somewhere. If you try using a "western" name, that will at least help us diagnose if that is the source of the problem.
• Some sort of network failure has caused the template be corrupted. If you delete the contents of the Briefcase cache folder (it should be in C:\Users\yaowe\AppData\Local\BeeWare\briefcase) and try re-running the new project wizard, that might fix the problem
• If it doesn't - check that the Briefcase new project template (it should be stored at C:\Users\yaowe\AppData\Local\BeeWare\briefcase\Cache\templates\briefcase-template) matches the content here. In particular, the hooks/pre_gen_project.py script is what is failing to run - if the content hasn't been downloaded correctly, that could cause the error you describe. This could be caused by external factors such as the Great Firewall of China.

[Naonao9527]

I just follw the direction of the official docmention to setup a new project.
Today,I replace my name as English,but the process failed again.
The following is the log and what is shown in the powershell.Also I upload a picture which shown the hooks/pre_gen_project.py.

briefcase.2026_02_27-11_39_09.new.log

[helloworld] Generating a new application 'Hello World'
Using app template: https://github.com/beeware/briefcase-template, branch v0.3.26
Cloning template 'https://github.com/beeware/briefcase-template'...
Using existing template (sha e16f77d8521be0db2a03e71db27a387cbed466bf, updated Sun Nov 30 18:49:06 2025)
Stopping generation because pre_gen_project hook script didn't exit successfully

Log saved to D:\Projects\new_dir\logs\briefcase.2026_02_28-08_40_39.new.log

Traceback (most recent call last):
File "", line 198, in run_module_as_main
File "", line 88, in run_code
File "D:\Projects\new_dir.venv\Scripts\briefcase.exe_main.py", line 7, in
sys.exit(main())
~~~~^^
File "D:\Projects\new_dir.venv\Lib\site-packages\briefcase_main.py", line 27, in main
command(**options)
~~~~~~~^^^^^^^^^^^
File "D:\Projects\new_dir.venv\Lib\site-packages\briefcase\commands\new.py", line 611, in call
return self.new_app(
~~~~~~~~~~~~^
template=template,
^^^^^^^^^^^^^^^^^^
...<2 lines>...
**options,
^^^^^^^^^^
)
^
File "D:\Projects\new_dir.venv\Lib\site-packages\briefcase\commands\new.py", line 564, in new_app
self.generate_template(
~~~~~~~~~~~~~~~~~~~~~~^
template=(
^^^^^^^^^^
...<6 lines>...
extra_context=context,
^^^^^^^^^^^^^^^^^^^^^^
)
^
File "D:\Projects\new_dir.venv\Lib\site-packages\briefcase\commands\base.py", line 1324, in generate_template
self._generate_template(
~~~~~~~~~~~~~~~~~~~~~~~^
template=template,
^^^^^^^^^^^^^^^^^^
...<2 lines>...
extra_context=extra_context,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "D:\Projects\new_dir.venv\Lib\site-packages\briefcase\commands\base.py", line 1266, in _generate_template
self.tools.cookiecutter(
~~~~~~~~~~~~~~~~~~~~~~~^
str(cached_template),
^^^^^^^^^^^^^^^^^^^^^
...<8 lines>...
default_config={"replay_dir": str(self.template_cache_path(".replay"))},
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "D:\Projects\new_dir.venv\Lib\site-packages\cookiecutter\main.py", line 182, in cookiecutter
result = generate_files(
repo_dir=repo_dir,
...<5 lines>...
keep_project_on_failure=keep_project_on_failure,
)
File "D:\Projects\new_dir.venv\Lib\site-packages\cookiecutter\generate.py", line 342, in generate_files
run_hook_from_repo_dir(
~~~~~~~~~~~~~~~~~~~~~~^
repo_dir, 'pre_gen_project', project_dir, context, delete_project_on_failure
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "D:\Projects\new_dir.venv\Lib\site-packages\cookiecutter\hooks.py", line 157, in run_hook_from_repo_dir
run_hook(hook_name, project_dir, context)
~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\Projects\new_dir.venv\Lib\site-packages\cookiecutter\hooks.py", line 140, in run_hook
run_script_with_context(script, project_dir, context)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\Projects\new_dir.venv\Lib\site-packages\cookiecutter\hooks.py", line 123, in run_script_with_context
run_script(temp.name, cwd)
~~~~~~~~~~^^^^^^^^^^^^^^^^
File "D:\Projects\new_dir.venv\Lib\site-packages\cookiecutter\hooks.py", line 94, in run_script
raise FailedHookException(
f'Hook script failed (exit status: {exit_status})'
)
cookiecutter.exceptions.FailedHookException: Hook script failed (exit status: 1)

[freakboy3742]

Thanks for those details - it looks like there's no problem with a corrupted file; so there's something else going on.

The next thing to try is to use the cookiecutter template directly, and see if you get a more helpful error message. With your Briefcase virtual environment activated, try running:

cookiecutter --no-input git+https://github.com/beeware/briefcase-template.git 

Do you still get the same error? A different error? If so - what is it?

Has a helloworld folder been created? If so - can you please create a zip file of that folder and attach a copy to this ticket.

If you don't get an error, delete the helloworld folder that was just created, and try running:

cookiecutter git+https://github.com/beeware/briefcase-template.git 

and provide the same answers to the questions as you do to Briefcase. Do you get an error this time?

[Naonao9527]

The error is as follows：

[freakboy3742]

Ok - that's an error I saw last week on the main branch of Briefcase. I thought it was only a warning that shouldn't affect normal operation, but it looks like it might be causing other problems (or something in cookiecutter is turning the warning into a full error).

If you python -m pip install chardet<6 in your Briefcase virtual environment, this might fix the problem. Let me know if that works.

[Naonao9527]

I reinstall it .but it still failed.

[freakboy3742]

Ok - can I get you to repeat the cookiecutter experiment with the new chardet installed?

[freakboy3742]

I believe we've found the source of this problem - one of our downstream dependencies (binaryornot) introduced a bug in their 0.5.0 release. As a workaround, python -m pip install briefcase binaryornot<0.5.0 should fix the issue.