dotenv parsing error should stop script

[mtmail]

1. I have an existing database called nominatim with a country import, so the default NOMINATIM_DATABASE_DSN=pgsql:dbname=nominatim or not setting NOMINATIM_DATABASE_DSN works.

2. Create a second project directory on the same server. But have an unparsable line in the .env file

   cat ~/nominatim-test-2/.env
   NOMINATIM_DATABASE_DSN='pgsql:dbname=nominatim_test_2
   

3. Don't run an import yet.

   $ psql -l
                                     List of databases
      Name    |  Owner   | Encoding |   Collate   |    Ctype    |   Access privileges
   -----------+----------+----------+-------------+-------------+-----------------------
    nominatim | ubuntu   | UTF8     | en_US.UTF-8 | en_US.UTF-8 |
    postgres  | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 |
   

4. Run nominatim admin --check-database. It prints a warning but continues and connects to the default database.

    ~/nominatim-test-2 $ nominatim admin --check-database
   2024-05-23 10:43:03: Python-dotenv could not parse statement starting at line 1.     <====
   2024-05-23 10:43:03: Using project directory: /home/ubuntu/nominatim-test-2
   2024-05-23 10:43:03: Checking database
   Checking database connection ... OK
   Checking database_version matches Nominatim software version ... OK
   Checking for placex table ... OK
   Checking for placex content ... OK
   Checking that tokenizer works ... OK
   

I'd argue Nominatim should treat parsing errors as fatal.

[lonvia]

I agree that we should bail out. Sadly, this is not supported by our dotenv implementation. There is an open issue here.

[mtmail]

I created a PR theskumar/python-dotenv#520 for dotenv project.