Flask 2.0.0 - ImportError: cannot import name '_endpoint_from_view_func' from 'flask.helpers'

[jloehel]

The helper function is not longer available in Flask 2.0.0

flask-restful/flask-restful#913

[dendisuhubdy]

yes broke my pipeline

[j5awry]

Thanks for catching this quickly. I've told Github to run the tests. on the PR. I don't foresee any issues there. I'll get this merged into main, and then cut a release ASAP.

[jziem]

flask-restful ran into same problem and fixed that issue: flask-restful/flask-restful#914

[cedricbonhomme]

Hello. Thank you for this fix. I did something similar in my venv. Are you going to publish the fix soonish on pypi ?

[cedricbonhomme]

Seems it is published on pypi, nice @j5awry . But there is a dependency issue with Flask 2.0, probably due to this:
https://github.com/python-restx/flask-restx/blob/master/requirements/install.pip#L4

$ poetry install
Creating virtualenv statsservice-eyi4DPj7-py3.9 in /home/cedric/.cache/pypoetry/virtualenvs
Updating dependencies
Resolving dependencies... (3.9s)

  SolverProblemError

  Because flask-restx (0.4.0) depends on Flask (>=0.8,<2.0.0)
   and no versions of flask-restx match >0.4.0,<0.5.0, flask_restx (>=0.4.0,<0.5.0) requires Flask (>=0.8,<2.0.0).
  So, because statsservice depends on both Flask (^2.0.0) and flask_restx (^0.4.0), version solving failed.

  at ~/.poetry/lib/poetry/puzzle/solver.py:241 in _solve
      237│             packages = result.packages
      238│         except OverrideNeeded as e:
      239│             return self.solve_in_compatibility_mode(e.overrides, use_latest=use_latest)
      240│         except SolveFailure as e:
    → 241│             raise SolverProblemError(e)
      242│ 
      243│         results = dict(
      244│             depth_first_search(
      245│                 PackageNode(self._package, packages), aggregate_package_nodes

[MoSehsah]

@cedricbonhomme I think sometimes this happens if you are using the same venv. Try to clear all packages from this venv and rerun pip again

[cedricbonhomme]

I deleted it, even cleaned the cache of poetry. Actually in the archive here it is written ''Flask>=0.8, <2.0.0''. So it seems poetry is right.

[j5awry]

check your config.toml and pyproject.toml as well, or any place dependencies are being specified. statsservice (which i assume is your poetry proejct) is depending on Flask ^2.0.0 somewhere. So you should set in your dependencies explicitly to Flask < 2.0.0 or delete a pinned line somewhere. It's also possible that there's a pinned dependency file somewhere being generated by poetry for repeatability. you might need to grep around. < 2.0.0 would not require 2.0.0. It'd require anything less than. >= 2.0.0 would require 2.0.0

[cedricbonhomme]

In the pyproject.toml I have these lines:

Flask = "^2.0.0"
flask_restx = "^0.4.0"
...
...

To be sure I have deleted the lock file (poetry.lock). As well deleted the virtual env and cleaned the cache of poetry. I am not using a config.toml file.

What I do not understand it's this:
https://github.com/python-restx/flask-restx/blob/master/requirements/install.pip#L4
it seems it excludes verion 2.0.0 of Flask. Is this correct ?

On a new project:

cedric@numero5:~$ mkdir newproject
cedric@numero5:~$ cd newproject/
cedric@numero5:~/newproject$ poetry init   

This command will guide you through creating your pyproject.toml config.

Package name [newproject]:  
Version [0.1.0]:  
Description []:  
Author [Cédric Bonhomme <cedric@cedricbonhomme.org>, n to skip]:  
License []:  
Compatible Python versions [^3.9]:  

Would you like to define your main dependencies interactively? (yes/no) [yes] 
You can specify a package in the following forms:
  - A single name (requests)
  - A name and a constraint (requests@^2.23.0)
  - A git url (git+https://github.com/python-poetry/poetry.git)
  - A git url with a revision (git+https://github.com/python-poetry/poetry.git#develop)
  - A file path (../my-package/my-package.whl)
  - A directory (../my-package/)
  - A url (https://example.com/packages/my-package-0.1.0.tar.gz)

Search for package to add (or leave blank to continue): 

Would you like to define your development dependencies interactively? (yes/no) [yes] 
Search for package to add (or leave blank to continue): 

Generated file

[tool.poetry]
name = "newproject"
version = "0.1.0"
description = ""
authors = ["Cédric Bonhomme <cedric@cedricbonhomme.org>"]

[tool.poetry.dependencies]
python = "^3.9"

[tool.poetry.dev-dependencies]

[build-system]
requires = ["poetry-core>=1.0.0"]
build-backend = "poetry.core.masonry.api"


Do you confirm generation? (yes/no) [yes] 
cedric@numero5:~/newproject$ 
cedric@numero5:~/newproject$ 
cedric@numero5:~/newproject$ 
cedric@numero5:~/newproject$ ls -lh
total 4,0K
-rw-rw-r-- 1 cedric cedric 296 mai   12 17:10 pyproject.toml
cedric@numero5:~/newproject$ 
cedric@numero5:~/newproject$ 
cedric@numero5:~/newproject$ poetry install
Creating virtualenv newproject-Ur5O_nme-py3.9 in /home/cedric/.cache/pypoetry/virtualenvs
Updating dependencies
Resolving dependencies... (0.1s)

Writing lock file
cedric@numero5:~/newproject$ poetry add Flask
Using version ^2.0.0 for Flask

Updating dependencies
Resolving dependencies... (7.0s)

Writing lock file

Package operations: 6 installs, 0 updates, 0 removals

  • Installing markupsafe (2.0.0)
  • Installing click (8.0.0)
  • Installing itsdangerous (2.0.0)
  • Installing jinja2 (3.0.0)
  • Installing werkzeug (2.0.0)
  • Installing flask (2.0.0)
cedric@numero5:~/newproject$ poetry add flask_restx
Using version ^0.4.0 for flask-restx

Updating dependencies
Resolving dependencies... (0.1s)

  SolverProblemError

  Because no versions of flask-restx match >0.4.0,<0.5.0
   and flask-restx (0.4.0) depends on Flask (>=0.8,<2.0.0), flask-restx (>=0.4.0,<0.5.0) requires Flask (>=0.8,<2.0.0).
  So, because newproject depends on both Flask (^2.0.0) and flask-restx (^0.4.0), version solving failed.

  at ~/.poetry/lib/poetry/puzzle/solver.py:241 in _solve
      237│             packages = result.packages
      238│         except OverrideNeeded as e:
      239│             return self.solve_in_compatibility_mode(e.overrides, use_latest=use_latest)
      240│         except SolveFailure as e:
    → 241│             raise SolverProblemError(e)
      242│ 
      243│         results = dict(
      244│             depth_first_search(
      245│                 PackageNode(self._package, packages), aggregate_package_nodes

[frank2411]

I have the same problem as @cedricbonhomme. But directly with pip :)

[jloehel]

it seems it excludes verion 2.0.0 of Flask. Is this correct ?

Yes, there are more steps to go. This isn't the only issue. For now it's better to use Flask 1.1.2 together with flask-restx. I am not so familiar with poetry but I think it should be:

Flask = "^1.1.2"

which is equal with:

>=1.1.2 <2.0.0

[cedricbonhomme]

exactly, that's the point (as you say).

But this release (v 0.4.0) of Flask-restx is supposed to work with Flask 2.0.

[j5awry]

@cedricbonhomme No, it does not work with Flask 2.0.0. Hence the pin. There are other issues around Werkzeug and Flask that our CI pipeline tests found. We have pinned to < 2.0.0 for Flask and werkzeug until upstream bugs are addressed, and we can fix all calls in our code.

we fixed a single bug someone found, but the pipeline found more, some of which are upstream

[cedricbonhomme]

OK, thanks. Now I understand. My project actually works with Flask 2 and flask-restx 0.4.0 (i changed the lib in the venv manually). I will see if I can contribute to fix the errors I might have.

[jloehel]

@cedricbonhomme You can install flask-restx also with --no-deps. I am not sure about the equivalent in poetry. It should be not necessary to patch it.

[j5awry]

it's entirely possible that specific projects will work with Flask and werkzeug 2.0.0. Our tests are failing due to some specific tests. here's an example of a failure: https://github.com/python-restx/flask-restx/runs/2565726592

at least one is related to something report upstream to werkzeug: pallets/werkzeug#2115

we'll need to dig through a bit to see all possible interactions. I'll open a separate issue specifically to track upgrading flask and werkzeug to 2.0.0

[j5awry]

#313 opened to track unpinning and fixing any other issues we find with upgrading flask and werkzeug