diff --git a/colcon_clean/base_handler/__init__.py b/colcon_clean/base_handler/__init__.py
index 65efcb6..ce7aa98 100644
--- a/colcon_clean/base_handler/__init__.py
+++ b/colcon_clean/base_handler/__init__.py
@@ -74,7 +74,7 @@ def add_base_handler_arguments(parser):
         choices=extension_keys,
         default=extension_keys,
         help='Select base names to clean in workspace '
-             '(default: {extension_keys})'.format_map(locals()))
+             f'(default: {extension_keys})')
 
     group.add_argument(
         '--base-ignore', nargs='*', metavar='BASE_NAME',
diff --git a/colcon_clean/base_handler/build.py b/colcon_clean/base_handler/build.py
index 1a9aee8..8fb504f 100644
--- a/colcon_clean/base_handler/build.py
+++ b/colcon_clean/base_handler/build.py
@@ -22,7 +22,7 @@ def add_arguments(self, *, parser):  # noqa: D102
             '--build-base',
             default=self.base_path,
             help='The base path for all build directories '
-                 '(default: {self.base_path})'.format_map(locals()))
+                 f'(default: {self.base_path})')
 
     def get_workspace_paths(self, *, args):  # noqa: D102
         return [args.build_base]
diff --git a/colcon_clean/base_handler/install.py b/colcon_clean/base_handler/install.py
index dbcb8ef..c841839 100644
--- a/colcon_clean/base_handler/install.py
+++ b/colcon_clean/base_handler/install.py
@@ -22,7 +22,7 @@ def add_arguments(self, *, parser):  # noqa: D102
             '--install-base',
             default=self.base_path,
             help='The base path for all install directories '
-                 '(default: {self.base_path})'.format_map(locals()))
+                 f'(default: {self.base_path})')
 
     def get_workspace_paths(self, *, args):  # noqa: D102
         return [args.install_base]
diff --git a/colcon_clean/base_handler/log.py b/colcon_clean/base_handler/log.py
index 2f9e5ad..edf1d1a 100644
--- a/colcon_clean/base_handler/log.py
+++ b/colcon_clean/base_handler/log.py
@@ -20,7 +20,7 @@ def add_arguments(self, *, parser):  # noqa: D102
             '--log-base',
             default=self.base_path,
             help='The base path for all log directories '
-                 '(default: {self.base_path})'.format_map(locals()))
+                 f'(default: {self.base_path})')
 
     def get_workspace_paths(self, *, args):  # noqa: D102
         return [args.log_base]
diff --git a/colcon_clean/base_handler/test_result.py b/colcon_clean/base_handler/test_result.py
index e554676..a6e2ac7 100644
--- a/colcon_clean/base_handler/test_result.py
+++ b/colcon_clean/base_handler/test_result.py
@@ -24,7 +24,7 @@ def add_arguments(self, *, parser):  # noqa: D102
             '--test-result-base',
             default=self.base_path,
             help='The base path for all test_result directories '
-                 '(default: {self.base_path})'.format_map(locals()))
+                 f'(default: {self.base_path})')
 
     def get_workspace_paths(self, *, args):  # noqa: D102
         return [args.test_result_base]
diff --git a/colcon_clean/subverb/__init__.py b/colcon_clean/subverb/__init__.py
index 03d121d..4ed0631 100644
--- a/colcon_clean/subverb/__init__.py
+++ b/colcon_clean/subverb/__init__.py
@@ -242,20 +242,17 @@ def clean_paths(paths, confirmed=False):
             _clean_path(path)
 
 
-def _onerror(func, path, excinfo):  # pragma: no cover
-    if excinfo[0] in (OSError, PermissionError):  # pragma: no branch
-        logger.warning(
-            "Skipping path: '{path}'".format_map(locals()))
-        logger.info(
-            "Skipping info: '{excinfo[1]}'".format_map(locals()))
+def _onexc(func, path, excinfo):  # pragma: no cover
+    if isinstance(excinfo, (PermissionError, OSError)):  # pragma: no branch
+        logger.warning(f"Skipping path: '{path}'")
+        logger.info(f"Skipping info: '{excinfo}'")
         return
     raise
 
 
 def _clean_path(path):
-    logger.info(
-        "Cleaning path: '{path}'".format_map(locals()))
+    logger.info(f"Cleaning path: '{path}'")
     if path.is_dir():
-        shutil.rmtree(path, onerror=_onerror)
+        shutil.rmtree(path, onexc=_onexc)
     else:
         path.unlink()
diff --git a/colcon_clean/subverb/packages.py b/colcon_clean/subverb/packages.py
index fc12838..8bbdffe 100644
--- a/colcon_clean/subverb/packages.py
+++ b/colcon_clean/subverb/packages.py
@@ -48,9 +48,7 @@ def main(self, *, context):  # noqa: D102
 
         for base_name in args.base_select:
             if base_name in args.base_ignore:
-                logger.info(
-                    "Ignoring base handler for selection '{base_name}'"
-                    .format_map(locals()))
+                logger.info(f"Ignoring base handler for selection '{base_name}'")
                 continue
             base_handler_extension = base_handler_extensions[base_name]
             for decorator in decorators:
diff --git a/colcon_clean/subverb/workspace.py b/colcon_clean/subverb/workspace.py
index 2dff71b..c22408e 100644
--- a/colcon_clean/subverb/workspace.py
+++ b/colcon_clean/subverb/workspace.py
@@ -43,9 +43,7 @@ def main(self, *, context):  # noqa: D102
 
         for base_name in args.base_select:
             if base_name in args.base_ignore:
-                logger.info(
-                    "Ignoring base handler for selection '{base_name}'"
-                    .format_map(locals()))
+                logger.info(f"Ignoring base handler for selection '{base_name}'")
                 continue
             base_handler_extension = base_handler_extensions[base_name]
             workspace_paths = \
diff --git a/test/spell_check.words b/test/spell_check.words
index 340dbb5..a7f70f2 100644
--- a/test/spell_check.words
+++ b/test/spell_check.words
@@ -19,6 +19,7 @@ mkdtemp
 monkeypatch
 nargs
 noqa
+onexc
 pathlib
 plugin
 pydocstyle