Hl everyone, Tl;DR: if you (as a number of our users) experienced issues with installing Airflow 2 over the last 2 days, the problem should be workarounded now for all versions of Airflow 2 and it should install properly even with the latest setuptools.
Context: The recent setuptools release (58.0.2) has broken installation for ALL Airflow 2 released versions (Details of the issue here: https://github.com/apache/airflow/issues/18075 ). The actual problem is the deprecation of 2_to_3 configuration in FlaskOpenID. We try to communicate with FlaskOpenId maintainers, but it's likely they won't fix it (the last release was in 2016) This was rather unfortunate, because setuptools need to be installed before airflow and even with our constraint mechanisms, we cannot force setuptools to be downgraded. Solution (Workaround really): Luckily, (with the help of TP, our PIP expert :) ) we've figured out and implemented the workaround, so as long as you use the "official" way of installing airflow (with constraints), Airflow should continue to install even with the latest setuptools. Details of the workaround in https://github.com/apache/airflow/issues/18075#issuecomment-915145181 We basically forked Flask-OpenID, applied removal of the deprecated option and updated the constraints to include our patched version. I applied the fix to constraints for all released Airflow 2 versions: * 2.1.3: https://github.com/apache/airflow/commit/64508c7c974f56ac05a919deca0b69ad1b9df19e * 2.1.2: https://github.com/apache/airflow/commit/641d6cad2b7221e58fdc117a0faa3d12652a10b2 * 2.1.1: https://github.com/apache/airflow/commit/cf0834b1da66ad8424ecb6344c799a1e9a6abe2e * 2.1.0: https://github.com/apache/airflow/commit/1e52c69c608c417c9466dd512e4cd46a65dbad68 * 2.0.2: https://github.com/apache/airflow/commit/82cc57b5f96f08f6d5976b3e6a3ea33b3b5459d0 * 2.0.1: https://github.com/apache/airflow/commit/2984d415c1fd9cf535cacf26b57666acadf24706 * 2.0.0: https://github.com/apache/airflow/commit/dd3e88fd6414ca9fda7108088a959e709b45037f J.
