Fatal on CLI invocation for python 2.7 1.10.10

[schrockn]

Python Version: Python 2.7.17
Apache Airflow version: 1.10.10

Environment:

• Cloud provider or hardware configuration: MacOS
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a): Darwin elementl-mbppro-2019.local 19.4.0 Darwin Kernel Version 19.4.0: Wed Mar 4 22:28:40 PST 2020; root:xnu-6153.101.6~15/RELEASE_X86_64 x86_64
• Install tools: pip and virtualenv
• Others:

What happened:

(debug-airflow-2.7-04-19-2020) [schrockn@mbp ~/code/dagster (fix-airflow)]$ airflow
Traceback (most recent call last):
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/bin/airflow", line 26, in <module>
    from airflow.bin.cli import CLIFactory
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/lib/python2.7/site-packages/airflow/bin/cli.py", line 79, in <module>
    api_module = import_module(conf.get('cli', 'api_client'))  # type: Any
  File "/Users/schrockn/.pyenv/versions/2.7.17/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/lib/python2.7/site-packages/airflow/api/client/local_client.py", line 24, in <module>
    from airflow.api.common.experimental import delete_dag
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/lib/python2.7/site-packages/airflow/api/common/experimental/delete_dag.py", line 25, in <module>
    from airflow.models.serialized_dag import SerializedDagModel
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/lib/python2.7/site-packages/airflow/models/serialized_dag.py", line 32, in <module>
    from airflow.serialization.serialized_objects import SerializedDAG
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/lib/python2.7/site-packages/airflow/serialization/serialized_objects.py", line 28, in <module>
    import cattr
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/lib/python2.7/site-packages/cattr/__init__.py", line 1, in <module>
    from .converters import Converter, UnstructureStrategy
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/lib/python2.7/site-packages/cattr/converters.py", line 15, in <module>
    from ._compat import (
  File "/Users/schrockn/venvs/debug-airflow-2.7-04-19-2020/lib/python2.7/site-packages/cattr/_compat.py", line 2, in <module>
    from functools import lru_cache, singledispatch  # noqa
ImportError: cannot import name lru_cache

What you expected to happen: Expect the airflow help string to print

How to reproduce it: Any cli invocation

Anything else we need to know:
More relevant modules:

cattrs                             0.9.1
backports.functools-lru-cache      1.6.1

[boring-cyborg]

Thanks for opening your first issue here! Be sure to follow the issue template!

[schrockn]

This appears to actually be because of cattrs. cattrs version 0.9.0 works fine.

[schrockn]

Tracking this here as well: https://github.com/Tinche/cattrs/issues/84

[potiuk]

Also see the information about using constraint files to install the dependencies that are guaranteed to work: https://github.com/apache/airflow/blob/v1-10-stable/CONTRIBUTING.rst#pinned-requirement-files

This installation method should work:

pip install apache-airflow[.... Some extras here]==1.10.10 \
    --constraint https://raw.githubusercontent.com/apache/airflow/1.10.10/requirements/requirements-python3.6.txt

This method is also used to prepare official airflow images.

In those requirement files cattrs are 0.9.0 version

[schrockn]

Thanks! Definitely looks like a cattrs issue, rather than anything on your end. Thanks for explanation. Feel free to close! Unfortunately because of the state of python dependency management I don't think this will be the first bug report like this.