Flask DB swallowing alembic errors.

[ilyail3]

Hey everyone.

I ran into an issue on prod system where a migration fails, but the error of why it failed is never displayed. All I see is the exit code: 1
No log line, or any other indication that something went wrong.

I stepped through the code, and found alembic raises: util.CommandError with the string:
Can't locate revision identified by '%s', but that error is never displayed.

I'm attaching pdb output of running the migration command until it exits:
`> /project/app.py(18)create_app()
-> app = Flask(name, static_url_path="/assets", static_folder="assets")
(Pdb) r
--Return--

/project/app.py(58)create_app()-><Flask 'some_app.app'>
-> return app
(Pdb) r
/project/.venv/lib/python3.11/site-packages/flask/cli.py(178)find_app_by_string()
-> if isinstance(app, Flask):
(Pdb) r
--Return--
/project/.venv/lib/python3.11/site-packages/flask/cli.py(179)find_app_by_string()-><Flask 'shipi...p_server.app'>
-> return app
(Pdb) r
--Return--
/project/.venv/lib/python3.11/site-packages/flask/cli.py(237)locate_app()-><Flask 'some_app.app'>
-> return find_app_by_string(module, app_name)
(Pdb) r
/project/.venv/lib/python3.11/site-packages/flask/cli.py(317)load_app()
-> if not app:
(Pdb) r
--Return--
/project/.venv/lib/python3.11/site-packages/flask/cli.py(331)load_app()-><Flask 'some_app.app''>
-> return app
(Pdb) r
/project/.venv/lib/python3.11/site-packages/flask/cli.py(586)get_command()
-> if not current_app or current_app._get_current_object() is not app:
(Pdb) r
--Return--
/project/.venv/lib/python3.11/site-packages/flask/cli.py(589)get_command()->
-> return app.cli.get_command(ctx, name)
(Pdb) r
/project/.venv/lib/python3.11/site-packages/click/core.py(1702)resolve_command()
-> if cmd is None and ctx.token_normalize_func is not None:
(Pdb) r
--Return--
/project/.venv/lib/python3.11/site-packages/click/core.py(1716)resolve_command()->('db', , ['upgrade'])
-> return cmd_name if cmd else None, cmd, args[1:]
(Pdb) r
/project/.venv/lib/python3.11/site-packages/click/core.py(1652)invoke()
-> assert cmd is not None
(Pdb) r
INFO [alembic.runtime.migration] Context impl PostgresqlImpl.
INFO [alembic.runtime.migration] Will assume transactional DDL.
--Return--
/project/.venv/lib/python3.11/site-packages/click/core.py(1657)invoke()->None
-> return _process_result(sub_ctx.command.invoke(sub_ctx))
(Pdb) r
SystemExit: 1
/project/.venv/lib/python3.11/site-packages/click/core.py(1055)main()
-> rv = self.invoke(ctx)
(Pdb) r
--Return--
/project/.venv/lib/python3.11/site-packages/click/core.py(1094)main()->None
-> except Abort:
(Pdb) r
SystemExit: 1
/project/.venv/lib/python3.11/site-packages/flask/cli.py(1047)main()
-> cli.main()
(Pdb) r
--Return--
/project/.venv/lib/python3.11/site-packages/flask/cli.py(1047)main()->None
-> cli.main()
(Pdb) r
SystemExit: 1
/project/.venv/bin/flask(8)()
-> sys.exit(main())
(Pdb) r
--Return--
/project/.venv/bin/flask(8)()->None
-> sys.exit(main())
(Pdb) r
`

I tried playing with logging settings in alembic.ini file, but nothing I did there produced the error, am I missing something, or is that a bug?