AttributeError: module 'os' has no attribute 'geteuid'

Bug description

Expected behaviour

Expect to produce docker image.

Actual behaviour

Traceback (most recent call last):
  File "c:\appdata\local\continuum\anaconda3\lib\site-packages\traitlets\traitlets.py", line 528, in get
    value = obj._trait_values[self.name]
KeyError: 'user_id'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\appdata\local\continuum\anaconda3\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\appdata\local\continuum\anaconda3\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\AppData\Local\Continuum\anaconda3\Scripts\repo2docker.exe\__main__.py", line 9, in <module>
  File "c:\appdata\local\continuum\anaconda3\lib\site-packages\repo2docker\__main__.py", line 345, in main
    r2d = make_r2d()
  File "c:\appdata\local\continuum\anaconda3\lib\site-packages\repo2docker\__main__.py", line 300, in make_r2d
    if r2d.user_id == 0 and not r2d.dry_run:
  File "c:\appdata\local\continuum\anaconda3\lib\site-packages\traitlets\traitlets.py", line 556, in __get__
    return self.get(obj, cls)
  File "c:\appdata\local\continuum\anaconda3\lib\site-packages\traitlets\traitlets.py", line 535, in get
    value = self._validate(obj, dynamic_default())
  File "c:\appdata\local\continuum\anaconda3\lib\site-packages\repo2docker\app.py", line 206, in _user_id_default
    return os.geteuid()
AttributeError: module 'os' has no attribute 'geteuid'

How to reproduce

1. On a Windows 10 PC, open the Anaconda Command Prompt
2. Run repo2docker https://github.com/matthewolckers/fbr2020

• OS: Windows 10
• Docker version: 19.03.8,
• repo2docker version 0.11.0

[manics]

AFAIK the only reason to make the UID inside the Docker image match the user’s UID is so that if you mount the user’s home directory into the container it’ll be writeable. Is that possible on Windows and if so, how are UIDs mapped, since that might lead to a good solution?

[ivergara]

I got to move from the original issue by forcing to run with a given GUID in the _user_id_default method.

    @default("user_id")
    def _user_id_default(self):
        """
        Default user_id to current running user.
        """
        if sys.platform == "win32" or not hasattr(os, "geteuid"):
            return 1001
        return os.geteuid()

With this change, the execution then stops working in step 31 when trying to execute install-miniforge.bash.

Step 30/50 : USER root
 ---> Using cache
 ---> 394ba1fe367c
Step 31/50 : RUN TIMEFORMAT='time: %3R' bash -c 'time /tmp/install-miniforge.bash' && rm /tmp/install-miniforge.bash /tmp/environment.yml
 ---> Running in cf91e3dafa9a
bash: /tmp/install-miniforge.bash: Permission denied
time: 0.001

My docker knowledge at this moment doesn’t go too deep as to know how to start digging deeper into this error/issue. Anyone here has a hint on how to progress here to diagnose the problem in an effective way?