Do not ignore non-existing files

handel/interface.py

@@ -363,7 +363,11 @@ def get_config_files(path):
 
 def get_config(filename):
     """Read and return the given config file as a dictionary."""
+    # Make sure the file exists
+    open(filename).close()
+    # Customize parser
     config = configparser.ConfigParser(
         comment_prefixes=['START', 'END', '#', '*****'])
+    # Read and parse
     config.read(filename)
     return {section: dict(config[section]) for section in config.sections()}

tests/test_interface.py

@@ -469,3 +469,5 @@ def test_get_config(interface):
     d = interface.get_config(filename)
     assert d['detector definitions']['alias'] == 'detector1'
     assert 'DEFAULT' not in d
+    with pytest.raises(FileNotFoundError):
+        interface.get_config('i_dont_exist.ini')