Error while install airflow: By default one of Airflow’s dependencies installs a GPL

Try the following:

export AIRFLOW_GPL_UNIDECODE=yes

OR

export SLUGIFY_USES_TEXT_UNIDECODE=yes

Using export makes the environment variable available to all the subprocesses.

Also, make sure you are using pip install apache-airflow[postgres] and not pip install airflow[postgres]

Which should you use: if using AIRFLOW_GPL_UNIDECODE, airflow will install a dependency that is under GPL license, which means you won’t be able to distribute your resulting application commercially. If that’s a problem for you, go for SLUGIFY_USES_TEXT_UNIDECODE.