Small changes

run.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+python -m ionbeam ./config -vvvv --env=local --init-db #--overwrite --offline 
+
+# To drop into a debugger on error, enable the -simple-output option first
+# python -m ionbeam config/ionbeam -vvvv --offline --finish-after=5 --simple-output --debug
+
+# Or just insert breakpoint() into the code and use --simple-output

src/ionbeam/core/config_parser/config_parser.py

@@ -125,6 +125,10 @@ def parse_globals(config_dir: Path, **overrides):
 
     # Based on the environment =dev/test/prod/local merge config into globals
     env = overrides.get("environment", config.globals.environment)
+    if env is None:
+        logger.debug("No environment specified, defaulting to 'local'")
+        env = "local"
+
     config.globals = merge_overlay(config.globals, config.environments[env])
 
     # Merge config from the command line into the global config keys

src/ionbeam/core/config_parser/config_parser_machinery.py

@@ -1,10 +1,9 @@
-from functools import cache
 import dataclasses
-from dataclasses import dataclass, field, Field
-import dataclasses # So we can override is_dataclass and fields with a custom implementation
-from typing import Union, get_origin, get_args, List
 import typing
+from dataclasses import Field, dataclass, field
 from pathlib import Path
+from typing import Union, get_args, get_origin
+
 from .common import ConfigError, ConfigMatchError
 
 # TYPE_KEY is a special key that determines which class or type to pick in ambiguous cases.
@@ -217,7 +216,7 @@ def parse_union(context, key, _type, value):
                 key,
                 _type,
                 value,
-                f"Union types of multiple non-dataclasses are not allowed"
+                "Union types of multiple non-dataclasses are not allowed"
                 " because there's no way to decide which one to use for parsing!",
             )
 
@@ -319,7 +318,7 @@ def dataclass_from_dict(context, datacls, input_dict):
 
     # initialise all the post_init fields to None, leaving it up to the caller to deal with them
     post_init_fields = {field.name : None for field in fields(datacls) 
-                        if is_post_init_field(field) and not field.name in kwargs}
+                        if is_post_init_field(field) and field.name not in kwargs}
 
     return datacls(**kwargs, **post_init_fields)