debugpy ImportError: cannot import name ``module_from_spec`` from ``importlib.util``

[gswifort]

debugpy ImportError: cannot import name module_from_spec from importlib.util

Environment

• OS: Windows 11
• Python Version: 3.12.7
• VS Code Version: Latest
• debugpy Extension Version: 2025.16.0-win32-x64

Description

When trying to debug a Python file using the "Current File" debug configuration in VS Code, debugpy fails to start with an ImportError claiming it cannot import module_from_spec from importlib.util. However, manual testing shows that this function is available and works correctly in the same Python environment.

Steps to Reproduce

1. Create a simple Python file (e.g., main.py with basic content)
2. Set up VS Code with Python extension and debugpy
3. Try to debug using "Current File" configuration (F5)
4. Observe the ImportError

Expected Behavior

The debugger should start successfully and allow debugging of the Python file.

Actual Behavior

debugpy fails to start with the following error:

ImportError: cannot import name 'module_from_spec' from 'importlib.util' (c:\Users\GSWI\AppData\Local\Programs\Python\Python312\Lib\importlib\util.py)

Full Error Log

D:\Users\GSWI\Documents\debugpy-bug> cmd /C "C:\Users\GSWI\AppData\Local\Programs\Python\Python312\python.exe c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\launcher 63437 -- D:\Users\GSWI\Documents\debugpy-bug\main.py "
Traceback (most recent call last):
  File "C:\Users\GSWI\AppData\Local\Programs\Python\Python312\Lib\runpy.py", line 198, in _run_module_as_main
    return _run_code(code, main_globals, None,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\GSWI\AppData\Local\Programs\Python\Python312\Lib\runpy.py", line 88, in _run_code
    exec(code, run_globals)
  File "c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\launcher/../..\debugpy\__main__.py", line 69, in <module>
    from debugpy.server import cli
  File "c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\launcher/../..\debugpy/..\debugpy\server\__init__.py", line 7, in <module>
    import debugpy._vendored.force_pydevd  # noqa
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\launcher/../..\debugpy/..\debugpy\_vendored\force_pydevd.py", line 44, in <module>
    preimport('pydevd', [
  File "c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\launcher/../..\debugpy/..\debugpy\_vendored\__init__.py", line 126, in preimport
    import_module(name)
  File "C:\Users\GSWI\AppData\Local\Programs\Python\Python312\Lib\importlib\__init__.py", line 90, in import_module  
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\_vendored\pydevd\pydevd.py", line 49, in <module>
    from _pydevd_bundle import pydevd_utils
  File "c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\_vendored\pydevd\_pydevd_bundle\pydevd_utils.py", line 11, in <module>
    from importlib.util import module_from_spec, spec_from_file_location
ImportError: cannot import name 'module_from_spec' from 'importlib.util' (C:\Users\GSWI\AppData\Local\Programs\Python\Python312\Lib\importlib\util.py)

Proof that module_from_spec is Available

Manual verification shows that module_from_spec is indeed available in the same Python environment:

>>> import importlib.util as u
>>> u.__file__
'C:\\Users\\GSWI\\AppData\\Local\\Programs\\Python\\Python312\\Lib\\importlib\\util.py'
>>> u.module_from_spec
<function module_from_spec at 0x0000028A14BC2AC0>

Debug Configuration Used

The issue occurs with the "Current File" debug configuration:

{
    "name": "Current File",
    "type": "debugpy",
    "request": "launch",
    "program": "${file}",
    "console": "integratedTerminal",
    "justMyCode": false,
}

Additional Context

• The function module_from_spec has been available in importlib.util since Python 3.4
• This appears to be an issue with how debugpy's bundled libraries are handling imports
• The error occurs in the vendored pydevd component within debugpy
• Regular Python execution works fine, only debugging is affected

Workaround

As a temporary solution, you can use remote debugging by manually starting debugpy from the command line:

1. Run the following command in the terminal:

   python -m debugpy --listen 5678 --wait-for-client main.py

2. Use the "Remote Attach" debug configuration in VS Code:

   {
       "name": "Remote Attach",
       "type": "debugpy",
       "request": "attach",
       "connect": {
           "host": "127.0.0.1",
           "port": 5678
       },
       "justMyCode": false
   }

3. Start debugging using this configuration (F5) after running the terminal command.

This bypasses the launcher issue and allows debugging functionality to work normally.

[rchiodo]

This works fine for me with the same version of Debugpy and Python. I would hazard a guess something in your workspace or environment is loading a different version of importlib.

What does your PYTHONPATH look like?

[rchiodo]

You might also have to modify the pydevd code (at c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\_vendored\pydevd\_pydevd_bundle\pydevd_utils.py) to print out where it thinks importlib is coming from. Something like this:

try:
    from importlib.util import module_from_spec, spec_from_file_location
except ImportError:
    print("importlib.util module_from_spec not found, printing information")
    import importlib.util as test
    print(test.__file__)

[gswifort]

This works fine for me with the same version of Debugpy and Python. I would hazard a guess something in your workspace or environment is loading a different version of importlib.

What does your PYTHONPATH look like?

PYTHONPATH is empty

[gswifort]

You might also have to modify the pydevd code (at c:\Users\GSWI\.vscode\extensions\ms-python.debugpy-2025.16.0-win32-x64\bundled\libs\debugpy\_vendored\pydevd\_pydevd_bundle\pydevd_utils.py) to print out where it thinks importlib is coming from. Something like this:

try:
from importlib.util import module_from_spec, spec_from_file_location
except ImportError:
print("importlib.util module_from_spec not found, printing information")
import importlib.util as test
print(test.file)

importlib.util module_from_spec not found, printing information
C:\Users\GSWI\AppData\Local\Programs\Python\Python312\Lib\importlib\util.py

[rchiodo]

module_from_spec seems to come from _bootstrap.py. Maybe try printing this after the failure:

    import importlib._bootstrap as bs
    print(bs.__file__)
    print(bs.module_from_spec)

[gswifort]

try:
    from importlib.util import module_from_spec, spec_from_file_location
except ImportError:
    print("importlib.util module_from_spec not found, printing information")
    import importlib.util as test
    print(test.__file__)
    import importlib._bootstrap as bs
    print(bs.__file__)
    print(bs.module_from_spec)

importlib.util module_from_spec not found, printing information
C:\Users\GSWI\AppData\Local\Programs\Python\Python312\Lib\importlib\util.py
C:\Users\GSWI\AppData\Local\Programs\Python\Python312\Lib\importlib\_bootstrap.py
<function module_from_spec at 0x00000239B13D2AC0>

[rchiodo]

Well then I don't understand why module_from_spec isn't found. Importlib.util should have this code in it:

"""Utility code for constructing importers, etc."""
from ._abc import Loader
from ._bootstrap import module_from_spec
from ._bootstrap import _resolve_name
from ._bootstrap import spec_from_loader
from ._bootstrap import _find_spec
from ._bootstrap_external import MAGIC_NUMBER
from ._bootstrap_external import _RAW_MAGIC_NUMBER
from ._bootstrap_external import cache_from_source
from ._bootstrap_external import decode_source
from ._bootstrap_external import source_from_cache
from ._bootstrap_external import spec_from_file_location

Maybe try that code in the except clause?

[gswifort]

I reinstalled Python, everything works. Sorry for the wasted time - this should have been the first step.