fsspec 2025.3.1 error on python 3.8

[narugo1992]

https://github.com/deepghs/imgutils/actions/runs/14158666336/job/39661212162

Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.8.18/x64/bin/hfutils", line 5, in <module>
    from hfutils.entry import hfutilscli
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/hfutils/entry/__init__.py", line 1, in <module>
    from .cli import cli as hfutilscli
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/hfutils/entry/cli.py", line 1, in <module>
    from .clone import _add_clone_subcommand
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/hfutils/entry/clone.py", line 9, in <module>
    from ..operate.base import REPO_TYPES, RepoTypeTyping
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/hfutils/operate/__init__.py", line 1, in <module>
    from .base import get_hf_client, get_hf_fs, list_all_with_pattern, list_files_in_repository
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/hfutils/operate/base.py", line 24, in <module>
    from huggingface_hub import HfApi, HfFileSystem
  File "<frozen importlib._bootstrap>", line 1039, in _handle_fromlist
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/huggingface_hub/__init__.py", line 962, in __getattr__
    submod = importlib.import_module(submod_path)
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/importlib/__init__.py", line 1[27](https://github.com/deepghs/imgutils/actions/runs/14158666336/job/39661212162#step:15:28), in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/huggingface_hub/hf_file_system.py", line 12, in <module>
    import fsspec
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/fsspec/__init__.py", line 3, in <module>
    from . import caching
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/fsspec/caching.py", line 40, in <module>
    MultiFetcher = Callable[list[[int, int]], bytes]  # Maps [(start, end)] to bytes
TypeError: 'type' object is not subscriptable
make: *** [Makefile:52: dataset] Error 1

only reproducable on fsspec 2025.3.1 + python3.8, on all platforms (ubuntu/windows/macos)

no this issue on fsspec 2025.3.0 (see: https://github.com/deepghs/imgutils/actions/runs/14156328031/job/39658736867, exactly the same script)

[martindurant]

I think we should simply have dropped py3.8, which is not supported anyway ( https://devguide.python.org/versions/ ). We could yank and repost 2025.3.1 to enforce this, but it would probably be easier for you to update your python.

[akozhin-yint]

2025.3.0...2025.3.1#diff-b5b11ba0fa84ed968b7b623bea0e68f873b3416d12776494a1163fd8f44c15a6R40

This line type hint is causign this error. Can we just replace it with something like Callable[List[Tuple[int, int]], bytes] ?

[bertsky]

I am also hitting this (via fsspec>=2023.5.0 -> huggingface-hub<1.0,>=0.14.1->transformers<=4.30.2->eynollah==0.3.1) on py38.

I think we should simply have dropped py3.8, which is not supported anyway ( https://devguide.python.org/versions/ ). We could yank and repost 2025.3.1 to enforce this, but it would probably be easier for you to update your python.

If changing the type hint to accommodate py38 is not an option for you, then please do yank the latest release for that version of Python.

(I can easily live with an older version of fsspec, but pip would drag in the latest on any Python version, and I do like to support py38 for my users as long as possible, despite the EOL).

[MoAly98]

We also hit this in our CI with python 3.8. If support for 3.8 is dropped already I suppose it would be helpful to specify this in the release logs ? if this will happen in a later release then maybe the newest one can be patched to avoid confusion? just needs to be made explicit

[narugo1992]

my solution is like this, add this into your requirements.txt

fsspec>=2024; python_version > '3.8'
fsspec>=2024,<=2025.3.0; python_version <= '3.8'

[amotl]

Hi there. We observed another spot of this and wanted to report about it.

Thoughts

I think the current release should be yanked, and a new one with the designated constraint adjusted should be released.
Because fsspec is so ubiquitous, and not everyone employs exact version pinning, specifically not for packages that are using the calendar versioning scheme, I think fsspec should go this extra mile, even despite Python 3.8 is officially EOL.

Solution

filesystem_spec/pyproject.toml

Line 11 in 8d314c0

requires-python = ">=3.8"

By doing it right, all the downstream package managers have a chance to also do the right thing, selecting a previous version of fsspec without much ado, and usually not cause much friction at all.

• Edit: I've submitted Project metadata: Increase minimum Python version to say >=3.9 #1817.