Skip PG version check in db diff util

Also exit with a non-zero status code when `indico db prepare` fails
e.g. due to an too-old PG version

bin/utils/db_diff.py

@@ -112,7 +112,7 @@ def main(dbname, verbose, reverse):
     _checked_call(verbose, ['createdb', '-T', 'indico_template', temp_dbname])
     try:
         env_override = {'INDICO_CONF_OVERRIDE': repr({'SQLALCHEMY_DATABASE_URI': _build_conn_string(temp_dbname)})}
-        _checked_call(verbose, ['indico', 'db', 'prepare'], env=env_override)
+        _checked_call(verbose, ['indico', 'db', 'prepare', '--force'], env=env_override)
 
         # create SQLAlchemy engines/connections for base and target db
         base_eng = create_engine(_build_conn_string(temp_dbname))

indico/cli/database.py

@@ -45,7 +45,8 @@ def cli(ctx, plugin=None, all_plugins=False):
 @click.option('--force', is_flag=True, help='Force using an older Postgres version')
 def prepare(force=False):
     """Initialize a new database (creates tables, sets alembic rev to HEAD)."""
-    return prepare_db(force=force)
+    if not prepare_db(force=force):
+        sys.exit(1)
 
 
 def _stamp(plugin=None, revision=None):

indico/core/db/sqlalchemy/migration.py

@@ -81,11 +81,11 @@ def _require_encoding(encoding):
 def prepare_db(empty=False, root_path=None, verbose=True, force=False):
     """Initialize an empty database (create tables, set alembic rev to HEAD)."""
     if not _require_pg_version(13, force=force):
-        return
+        return False
     if not _require_encoding('UTF8'):
-        return
+        return False
     if not _require_extensions('unaccent', 'pg_trgm'):
-        return
+        return False
     root_path = root_path or current_app.root_path
     tables = get_all_tables(db)
     if 'alembic_version' not in tables['public']:
@@ -116,5 +116,6 @@ def prepare_db(empty=False, root_path=None, verbose=True, force=False):
             for schema, schema_tables in sorted(tables.items()):
                 for t in schema_tables:
                     print(cformat('  * %{cyan}{}%{reset}.%{cyan!}{}%{reset}').format(schema, t))
-        return
+        return False
     create_all_tables(db, verbose=verbose, add_initial_data=(not empty))
+    return True