Also fix parse_config_file()

Signed-off-by: Timo Röhling <roehling@debian.org>

ament_flake8/ament_flake8/main.py

@@ -190,28 +190,42 @@ def get_flake8_style_guide(argv):
 
 
 def parse_config_file(config_file):
+    from flake8 import __version__ as flake8_version, __version_info__ as flake8_version_info
     from flake8.options import config, manager, aggregator
 
-    try:
-        # Support 4.0.0
-        opts_manager = manager.OptionManager(prog='flake8', version='4.0.0')
+    major_release = flake8_version_info[0]
+
+    if major_release >= 5:
+        opts_manager = manager.OptionManager(
+            version=flake8_version,
+            plugin_versions="",
+            parents=[]
+        )
         flake8_options.register_default_options(opts_manager)
+        cfg, cfg_dir = config.load_config(config_file, [])
 
         return aggregator.aggregate_options(
             opts_manager,
-            config.ConfigFileFinder('flake8', [], config_file),
+            cfg, cfg_dir,
             []
-        )
-    except TypeError:
-        opts_manager = manager.OptionManager(prog='flake8', version='3.0.0')
+        ), []
+
+    if major_release >= 3:
+        opts_manager = manager.OptionManager(prog='flake8', version=flake8_version)
         flake8_options.register_default_options(opts_manager)
 
         return aggregator.aggregate_options(
             opts_manager,
-            config.ConfigFileFinder('flake8', [], [config_file]),
+            config.ConfigFileFinder(
+                'flake8',
+                [],
+                config_file if major_release == 4 else [config_file]
+            ),
             []
         )
 
+    raise RuntimeError('flake8 is too old. Please upgrade to version 3.0.0 or newer')
+
 
 def generate_flake8_report(config_file, paths, excludes, max_line_length=None):
     opts, _ = parse_config_file(config_file)