Respect sys.flags.safe_path

[siddharthab]

In the following line, the script directory path is added even if Python was run with sys.flags.safe_path (most often by setting the env var PYTHONSAFEPATH=1).

ipykernel/hatch_build.py

Line 15 in b11d42c

sys.path.insert(0, str(here))

Not having the ability to set safe path causes problems when there are sibling Python files with names that clash with installed Python modules.

Thanks to @DonJayamanne for helping find the root cause in microsoft/vscode-jupyter#16235.

[Carreau]

I doubt this is the location that adds the problematic sys.path entry as this should be used only when building ipykernel wheels.

[Carreau]

$ python -m ipykernel --help-all | grep cwd  -A 5
--ignore-cwd
    Exclude the current working directory from sys.path
    Equivalent to: [--InteractiveShellApp.ignore_cwd=True]
--no-ignore-cwd
    Include the current working directory in sys.path
    Equivalent to: [--InteractiveShellApp.ignore_cwd=False]
...
--InteractiveShellApp.ignore_cwd=<Bool>
    If True, IPython will not add the current working directory to sys.path.
    When False, the current working directory is added to sys.path, allowing
    imports of modules defined in the current directory.
    Default: False
..
--IPKernelApp.ignore_cwd=<Bool>
    If True, IPython will not add the current working directory to sys.path.
    When False, the current working directory is added to sys.path, allowing
    imports of modules defined in the current directory.
    Default: False

Updating the kernel launch config file to pass this flag (or set a global configuration file with the proper configuration works:

{
  "argv": [
    "$python_interpreter",
    "-Xfrozen_modules=off",
    "-m",
    "ipykernel_launcher",
    "-f",
    "{connection_file}",
    "--ignore-cwd"
  ],
  "display_name": "global",
  "language": "python",
  "metadata": {
    "debugger": true
  }
}

or config file with:

c.InteractiveShellApp.ignore_cwd=False

[siddharthab]

Thank you!