diff --git a/NEWS b/NEWS
index 97499bde..c4f89344 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,7 @@
    handy for fetching borgmatic configuration from external scripts. See the documentation for more
    information:
    https://torsion.org/borgmatic/reference/command-line/actions/config-show/
+ * #1228: Adjust the "spot" check so error output includes more information about what failed.
  * #1236: Fix the "spot" check to skip hard links, as Borg doesn't produces hashes for them.
  * #1269: Fix the ZFS hook to support datasets with a "canmount" property of "noauto".
  * #1270: Follow symlinks when backing up borgmatic configuration files to support the "bootstrap"
diff --git a/borgmatic/actions/check.py b/borgmatic/actions/check.py
index ce0d894f..8418c5d9 100644
--- a/borgmatic/actions/check.py
+++ b/borgmatic/actions/check.py
@@ -717,7 +717,7 @@ def spot_check(
         )
         logger.debug(f'Paths in latest archive but not source paths: {truncated_archive_paths}')
         raise ValueError(
-            'Spot check failed: There are no source paths to compare against the archive',
+            'Spot check failed; there are no source paths to compare against the archive',
         )
 
     # Calculate the percentage delta between the source paths count and the archive paths count, and
@@ -731,19 +731,13 @@ def spot_check(
             width=MAX_SPOT_CHECK_PATHS_LENGTH,
             placeholder=' ...',
         )
-        logger.debug(
-            f'Paths in source paths but not latest archive: {truncated_exclusive_source_paths}',
-        )
         truncated_exclusive_archive_paths = textwrap.shorten(
             ', '.join(set(archive_paths) - rootless_source_paths) or 'none',
             width=MAX_SPOT_CHECK_PATHS_LENGTH,
             placeholder=' ...',
         )
-        logger.debug(
-            f'Paths in latest archive but not source paths: {truncated_exclusive_archive_paths}',
-        )
         raise ValueError(
-            f'Spot check failed: {count_delta_percentage:.2f}% file count delta between source paths and latest archive (tolerance is {spot_check_config["count_tolerance_percentage"]}%)',
+            f'Spot check failed\n{count_delta_percentage:.2f}% file count delta between source paths ({len(source_paths)} total) and latest archive ({len(archive_paths)} total); tolerance is {spot_check_config["count_tolerance_percentage"]}%\nOnly in source paths: {truncated_exclusive_source_paths}\nOnly in latest archive: {truncated_exclusive_archive_paths}',
         )
 
     failing_paths = compare_spot_check_hashes(
@@ -768,11 +762,8 @@ def spot_check(
             width=MAX_SPOT_CHECK_PATHS_LENGTH,
             placeholder=' ...',
         )
-        logger.debug(
-            f'Source paths with data not matching the latest archive: {truncated_failing_paths}',
-        )
         raise ValueError(
-            f'Spot check failed: {failing_percentage:.2f}% of source paths with data not matching the latest archive (tolerance is {data_tolerance_percentage}%)',
+            f'Spot check failed\n{failing_percentage:.2f}% of source paths ({len(failing_paths)} out of {len(source_paths)} checked) with data not matching the latest archive; tolerance is {data_tolerance_percentage}%\nSource paths with non-matching data: {truncated_failing_paths}',
         )
 
     logger.info(
diff --git a/borgmatic/config/generate.py b/borgmatic/config/generate.py
index 4d3cda78..e22c452c 100644
--- a/borgmatic/config/generate.py
+++ b/borgmatic/config/generate.py
@@ -168,9 +168,11 @@ def render_configuration(config):
         rendered,
         # Dumping certain values (integers, for instance) causes ruamel.yaml to append an
         # end-of-document "..." marker. Strip it.
-        transform=lambda dumped: dumped[: -len(RUAMEL_YAML_END_OF_DOCUMENT_MARKER)]
-        if dumped.endswith(RUAMEL_YAML_END_OF_DOCUMENT_MARKER)
-        else dumped,
+        transform=lambda dumped: (
+            dumped[: -len(RUAMEL_YAML_END_OF_DOCUMENT_MARKER)]
+            if dumped.endswith(RUAMEL_YAML_END_OF_DOCUMENT_MARKER)
+            else dumped
+        ),
     )
 
     return rendered.getvalue()
diff --git a/tests/unit/commands/test_arguments.py b/tests/unit/commands/test_arguments.py
index 0fad32e7..0606a1d2 100644
--- a/tests/unit/commands/test_arguments.py
+++ b/tests/unit/commands/test_arguments.py
@@ -329,10 +329,12 @@ def test_parse_arguments_for_actions_consumes_action_arguments_after_action_name
     remaining = flexmock()
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {action: action_namespace},
-        )
-        or remaining,
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {action: action_namespace},
+            )
+            or remaining
+        ),
     )
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {'action': flexmock(), 'other': flexmock()}
@@ -355,10 +357,12 @@ def test_parse_arguments_for_actions_consumes_action_arguments_with_alias():
     remaining = flexmock()
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {canonical or action: action_namespace},
-        )
-        or remaining,
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {canonical or action: action_namespace},
+            )
+            or remaining
+        ),
     )
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {
@@ -387,10 +391,12 @@ def test_parse_arguments_for_actions_consumes_multiple_action_arguments():
     other_namespace = flexmock(bar=3)
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {action: action_namespace if action == 'action' else other_namespace},
-        )
-        or (),
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {action: action_namespace if action == 'action' else other_namespace},
+            )
+            or ()
+        ),
     ).and_return(('other', '--bar', '3')).and_return('action', '--foo', 'true')
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {
@@ -420,10 +426,12 @@ def test_parse_arguments_for_actions_respects_command_line_action_ordering():
     action_namespace = flexmock(foo=True)
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {action: other_namespace if action == 'other' else action_namespace},
-        )
-        or (),
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {action: other_namespace if action == 'other' else action_namespace},
+            )
+            or ()
+        ),
     ).and_return(('action',)).and_return(('other', '--foo', 'true'))
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {
@@ -458,10 +466,12 @@ def test_parse_arguments_for_actions_applies_default_action_parsers():
 
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {action: namespaces.get(action)},
-        )
-        or (),
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {action: namespaces.get(action)},
+            )
+            or ()
+        ),
     ).and_return(())
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {
@@ -488,10 +498,12 @@ def test_parse_arguments_for_actions_consumes_global_arguments():
     action_namespace = flexmock()
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {action: action_namespace},
-        )
-        or ('--verbosity', 'lots'),
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {action: action_namespace},
+            )
+            or ('--verbosity', 'lots')
+        ),
     )
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {
@@ -516,10 +528,12 @@ def test_parse_arguments_for_actions_passes_through_unknown_arguments_before_act
     action_namespace = flexmock()
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {action: action_namespace},
-        )
-        or ('--wtf', 'yes'),
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {action: action_namespace},
+            )
+            or ('--wtf', 'yes')
+        ),
     )
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {
@@ -544,10 +558,12 @@ def test_parse_arguments_for_actions_passes_through_unknown_arguments_after_acti
     action_namespace = flexmock()
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {action: action_namespace},
-        )
-        or ('--wtf', 'yes'),
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {action: action_namespace},
+            )
+            or ('--wtf', 'yes')
+        ),
     )
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {
@@ -572,10 +588,12 @@ def test_parse_arguments_for_actions_with_borg_action_skips_other_action_parsers
     action_namespace = flexmock(options=[])
     flexmock(module).should_receive('get_subaction_parsers').and_return({})
     flexmock(module).should_receive('parse_and_record_action_arguments').replace_with(
-        lambda unparsed, parsed, parser, action, canonical=None: parsed.update(
-            {action: action_namespace},
-        )
-        or (),
+        lambda unparsed, parsed, parser, action, canonical=None: (
+            parsed.update(
+                {action: action_namespace},
+            )
+            or ()
+        ),
     ).and_return(())
     flexmock(module).should_receive('get_subactions_for_actions').and_return({})
     action_parsers = {