From 7b8be800a4a9788e942938775e5071195a614686 Mon Sep 17 00:00:00 2001
From: Dan Helfman <witten@torsion.org>
Date: Mon, 19 Jun 2023 16:18:47 -0700
Subject: [PATCH] Refactor arguments parsing to fix bootstrap action CLI issues
 (#712).

---
 NEWS                                         |   4 +-
 borgmatic/borg/borg.py                       |   5 +-
 borgmatic/commands/arguments.py              | 377 +++++++-------
 borgmatic/commands/borgmatic.py              |   2 +-
 borgmatic/commands/completion/actions.py     |  21 +-
 tests/integration/commands/test_arguments.py |  72 ++-
 tests/unit/commands/test_arguments.py        | 498 +++++++++++++------
 tests/unit/commands/test_borgmatic.py        |   2 +-
 8 files changed, 617 insertions(+), 364 deletions(-)

diff --git a/NEWS b/NEWS
index 6f230e4..50391a8 100644
--- a/NEWS
+++ b/NEWS
@@ -1,7 +1,7 @@
 1.7.15.dev0
  * #399: Add a documentation troubleshooting note for MySQL/MariaDB authentication errors.
- * #697: Extract borgmatic configuration from backup via "bootstrap" action—even when borgmatic
-   has no configuration yet!
+ * #697, #712: Extract borgmatic configuration from backup via "bootstrap" action—even when
+   borgmatic has no configuration yet!
  * #669: Add sample systemd user service for running borgmatic as a non-root user.
 
 1.7.14
diff --git a/borgmatic/borg/borg.py b/borgmatic/borg/borg.py
index 82fecc1..f815dfd 100644
--- a/borgmatic/borg/borg.py
+++ b/borgmatic/borg/borg.py
@@ -38,10 +38,7 @@ def run_arbitrary_borg(
         borg_command = tuple(options[:command_options_start_index])
         command_options = tuple(options[command_options_start_index:])
 
-        if (
-            borg_command
-            and borg_command[0] in borgmatic.commands.arguments.SUBPARSER_ALIASES.keys()
-        ):
+        if borg_command and borg_command[0] in borgmatic.commands.arguments.ACTION_ALIASES.keys():
             logger.warning(
                 f"Borg's {borg_command[0]} subcommand is supported natively by borgmatic. Try this instead: borgmatic {borg_command[0]}"
             )
diff --git a/borgmatic/commands/arguments.py b/borgmatic/commands/arguments.py
index 30ac3f9..2f978a3 100644
--- a/borgmatic/commands/arguments.py
+++ b/borgmatic/commands/arguments.py
@@ -1,18 +1,17 @@
-import argparse
 import collections
 import itertools
+import sys
 from argparse import Action, ArgumentParser
 
 from borgmatic.config import collect
 
-SUBPARSER_ALIASES = {
+ACTION_ALIASES = {
     'rcreate': ['init', '-I'],
     'prune': ['-p'],
     'compact': [],
     'create': ['-C'],
     'check': ['-k'],
     'config': [],
-    'config_bootstrap': [],
     'extract': ['-x'],
     'export-tar': [],
     'mount': ['-m'],
@@ -28,124 +27,192 @@ SUBPARSER_ALIASES = {
 }
 
 
-def get_unparsable_arguments(remaining_subparser_arguments):
+def get_subaction_parsers(action_parser):
     '''
-    Determine the remaining arguments that no subparsers have consumed.
+    Given an argparse.ArgumentParser instance, lookup the subactions in it and return a dict from
+    subaction name to subaction parser.
     '''
-    if remaining_subparser_arguments:
-        remaining_arguments = [
-            argument
-            for argument in dict.fromkeys(
-                itertools.chain.from_iterable(remaining_subparser_arguments)
-            ).keys()
-            if all(
-                argument in subparser_arguments
-                for subparser_arguments in remaining_subparser_arguments
-            )
-        ]
-    else:
-        remaining_arguments = []
+    if not action_parser._subparsers:
+        return {}
 
-    return remaining_arguments
-
-
-def parse_subparser_arguments(unparsed_arguments, subparsers):
-    '''
-    Given a sequence of arguments and a dict from subparser name to argparse.ArgumentParser
-    instance, give each requested action's subparser a shot at parsing all arguments. This allows
-    common arguments like "--repository" to be shared across multiple subparsers.
-
-    Return the result as a tuple of (a dict mapping from subparser name to a parsed namespace of
-    arguments, a list of remaining arguments not claimed by any subparser).
-    '''
-    arguments = collections.OrderedDict()
-    remaining_arguments = list(unparsed_arguments)
-    alias_to_subparser_name = {
-        alias: subparser_name
-        for subparser_name, aliases in SUBPARSER_ALIASES.items()
-        for alias in aliases
-    }
-    subcommand_parsers_mapping = {
-        'config': ['bootstrap'],
+    return {
+        subaction_name: subaction_parser
+        for group_action in action_parser._subparsers._group_actions
+        for subaction_name, subaction_parser in group_action.choices.items()
     }
 
-    # If the "borg" action is used, skip all other subparsers. This avoids confusion like
-    # "borg list" triggering borgmatic's own list action.
-    if 'borg' in unparsed_arguments:
-        subparsers = {'borg': subparsers['borg']}
 
-    for argument in remaining_arguments:
-        canonical_name = alias_to_subparser_name.get(argument, argument)
-        subparser = subparsers.get(canonical_name)
-
-        if not subparser:
-            continue
-
-        # If a parsed value happens to be the same as the name of a subparser, remove it from the
-        # remaining arguments. This prevents, for instance, "check --only extract" from triggering
-        # the "extract" subparser.
-        parsed, unused_remaining = subparser.parse_known_args(
-            [argument for argument in unparsed_arguments if argument != canonical_name]
+def get_subactions_for_actions(action_parsers):
+    '''
+    Given a dict from action name to an argparse.ArgumentParser instance, make a map from action
+    name to the names of contained sub-actions.
+    '''
+    return {
+        action: tuple(
+            subaction_name
+            for group_action in action_parser._subparsers._group_actions
+            for subaction_name in group_action.choices.keys()
         )
+        for action, action_parser in action_parsers.items()
+        if action_parser._subparsers
+    }
+
+
+def omit_values_colliding_with_action_names(unparsed_arguments, parsed_arguments):
+    '''
+    Given a sequence of string arguments and a dict from action name to parsed argparse.Namespace
+    arguments, return the string arguments with any values omitted that happen to be the same as
+    the name of a borgmatic action.
+
+    This prevents, for instance, "check --only extract" from triggering the "extract" action.
+    '''
+    remaining_arguments = list(unparsed_arguments)
+
+    for action_name, parsed in parsed_arguments.items():
         for value in vars(parsed).values():
             if isinstance(value, str):
-                if value in subparsers:
+                if value in ACTION_ALIASES.keys():
                     remaining_arguments.remove(value)
             elif isinstance(value, list):
                 for item in value:
-                    if item in subparsers:
+                    if item in ACTION_ALIASES.keys():
                         remaining_arguments.remove(item)
 
-        arguments[canonical_name] = None if canonical_name in subcommand_parsers_mapping else parsed
+    return tuple(remaining_arguments)
 
-    for argument in arguments:
-        if not arguments[argument]:
-            if not any(
-                subcommand in arguments for subcommand in subcommand_parsers_mapping[argument]
-            ):
-                raise ValueError(
-                    f'Missing subcommand for {argument}. Expected one of {subcommand_parsers_mapping[argument]}'
-                )
 
-    # If no actions are explicitly requested, assume defaults.
-    if not arguments and '--help' not in unparsed_arguments and '-h' not in unparsed_arguments:
-        for subparser_name in ('create', 'prune', 'compact', 'check'):
-            subparser = subparsers[subparser_name]
-            parsed, unused_remaining = subparser.parse_known_args(unparsed_arguments)
-            arguments[subparser_name] = parsed
+def parse_and_record_action_arguments(
+    unparsed_arguments, parsed_arguments, action_parser, action_name, canonical_name=None
+):
+    '''
+    Given unparsed arguments as a sequence of strings, parsed arguments as a dict from action name
+    to parsed argparse.Namespace, a parser to parse with, an action name, and an optional canonical
+    action name (in case this the action name is an alias), parse the arguments and return a list of
+    any remaining string arguments that were not parsed. Also record the parsed argparse.Namespace
+    by setting it into the given parsed arguments. Return None if no parsing occurs because the
+    given action doesn't apply to the given unparsed arguments.
+    '''
+    filtered_arguments = omit_values_colliding_with_action_names(
+        unparsed_arguments, parsed_arguments
+    )
 
-    remaining_arguments = list(unparsed_arguments)
+    if action_name not in filtered_arguments:
+        return tuple(unparsed_arguments)
 
-    # Now ask each subparser, one by one, to greedily consume arguments, from last to first. This
-    # allows subparsers to consume arguments before their parent subparsers do.
-    remaining_subparser_arguments = []
+    parsed, remaining = action_parser.parse_known_args(filtered_arguments)
+    parsed_arguments[canonical_name or action_name] = parsed
 
-    for subparser_name, subparser in reversed(subparsers.items()):
-        if subparser_name not in arguments.keys():
+    # Special case: If this is a "borg" action, greedily consume all arguments after (+1) the "borg"
+    # argument.
+    if action_name == 'borg':
+        borg_options_index = remaining.index('borg') + 1
+        parsed_arguments['borg'].options = remaining[borg_options_index:]
+        remaining = remaining[:borg_options_index]
+
+    return tuple(argument for argument in remaining if argument != action_name)
+
+
+def get_unparsable_arguments(remaining_action_arguments):
+    '''
+    Given a sequence of argument tuples (one tuple per action parser that parsed arguments),
+    determine the remaining arguments that no action parsers have consumed.
+    '''
+    if not remaining_action_arguments:
+        return ()
+
+    return tuple(
+        argument
+        for argument in dict.fromkeys(
+            itertools.chain.from_iterable(remaining_action_arguments)
+        ).keys()
+        if all(argument in action_arguments for action_arguments in remaining_action_arguments)
+    )
+
+
+def parse_arguments_for_actions(unparsed_arguments, action_parsers):
+    '''
+    Given a sequence of arguments and a dict from action name to argparse.ArgumentParser
+    instance, give each requested action's parser a shot at parsing all arguments. This allows
+    common arguments like "--repository" to be shared across multiple action parsers.
+
+    Return the result as a tuple of: (a dict mapping from action name to an argparse.Namespace of
+    parsed arguments, a list of strings of remaining arguments not claimed by any action parser).
+    '''
+    arguments = collections.OrderedDict()
+    help_requested = bool('--help' in unparsed_arguments or '-h' in unparsed_arguments)
+    remaining_action_arguments = []
+    alias_to_action_name = {
+        alias: action_name for action_name, aliases in ACTION_ALIASES.items() for alias in aliases
+    }
+
+    # If the "borg" action is used, skip all other action parsers. This avoids confusion like
+    # "borg list" triggering borgmatic's own list action.
+    if 'borg' in unparsed_arguments:
+        action_parsers = {'borg': action_parsers['borg']}
+
+    # Ask each action parser, one by one, to parse arguments.
+    for argument in unparsed_arguments:
+        action_name = argument
+        canonical_name = alias_to_action_name.get(action_name, action_name)
+        action_parser = action_parsers.get(action_name)
+
+        if not action_parser:
             continue
 
-        subparser = subparsers[subparser_name]
-        unused_parsed, remaining = subparser.parse_known_args(
-            [argument for argument in unparsed_arguments if argument != subparser_name]
-        )
-        remaining_subparser_arguments.append(remaining)
+        subaction_parsers = get_subaction_parsers(action_parser)
 
-    if remaining_subparser_arguments:
-        remaining_arguments = get_unparsable_arguments(remaining_subparser_arguments)
+        # Parse with subaction parsers, if any.
+        if subaction_parsers:
+            subactions_parsed = False
 
-    # Special case: If "borg" is present in the arguments, consume all arguments after (+1) the
-    # "borg" action.
-    if 'borg' in arguments:
-        borg_options_index = remaining_arguments.index('borg') + 1
-        arguments['borg'].options = remaining_arguments[borg_options_index:]
-        remaining_arguments = remaining_arguments[:borg_options_index]
+            for subaction_name, subaction_parser in subaction_parsers.items():
+                remaining_action_arguments.append(
+                    parse_and_record_action_arguments(
+                        unparsed_arguments,
+                        arguments,
+                        subaction_parser,
+                        subaction_name,
+                    )
+                )
 
-    # Remove the subparser names themselves.
-    for subparser_name, subparser in subparsers.items():
-        if subparser_name in remaining_arguments:
-            remaining_arguments.remove(subparser_name)
+                if subaction_name in arguments:
+                    subactions_parsed = True
 
-    return (arguments, remaining_arguments)
+            if not subactions_parsed:
+                if help_requested:
+                    action_parser.print_help()
+                    sys.exit(0)
+                else:
+                    raise ValueError(
+                        f"Missing sub-action after {action_name} action. Expected one of: {', '.join(get_subactions_for_actions(action_parsers)[action_name])}"
+                    )
+        # Otherwise, parse with the main action parser.
+        else:
+            remaining_action_arguments.append(
+                parse_and_record_action_arguments(
+                    unparsed_arguments, arguments, action_parser, action_name, canonical_name
+                )
+            )
+
+    # If no actions were explicitly requested, assume defaults.
+    if not arguments and not help_requested:
+        for default_action_name in ('create', 'prune', 'compact', 'check'):
+            default_action_parser = action_parsers[default_action_name]
+            remaining_action_arguments.append(
+                parse_and_record_action_arguments(
+                    tuple(unparsed_arguments) + (default_action_name,),
+                    arguments,
+                    default_action_parser,
+                    default_action_name,
+                )
+            )
+
+    return (
+        arguments,
+        get_unparsable_arguments(tuple(remaining_action_arguments))
+        if arguments
+        else unparsed_arguments,
+    )
 
 
 class Extend_action(Action):
@@ -164,7 +231,7 @@ class Extend_action(Action):
 
 def make_parsers():
     '''
-    Build a top-level parser and its subparsers and return them as a tuple.
+    Build a top-level parser and its action parsers and return them as a tuple.
     '''
     config_paths = collect.get_default_config_paths(expand_home=True)
     unexpanded_config_paths = collect.get_default_config_paths(expand_home=False)
@@ -283,14 +350,14 @@ def make_parsers():
         parents=[global_parser],
     )
 
-    subparsers = top_level_parser.add_subparsers(
+    action_parsers = top_level_parser.add_subparsers(
         title='actions',
         metavar='',
         help='Specify zero or more actions. Defaults to create, prune, compact, and check. Use --help with action for details:',
     )
-    rcreate_parser = subparsers.add_parser(
+    rcreate_parser = action_parsers.add_parser(
         'rcreate',
-        aliases=SUBPARSER_ALIASES['rcreate'],
+        aliases=ACTION_ALIASES['rcreate'],
         help='Create a new, empty Borg repository',
         description='Create a new, empty Borg repository',
         add_help=False,
@@ -336,9 +403,9 @@ def make_parsers():
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
-    transfer_parser = subparsers.add_parser(
+    transfer_parser = action_parsers.add_parser(
         'transfer',
-        aliases=SUBPARSER_ALIASES['transfer'],
+        aliases=ACTION_ALIASES['transfer'],
         help='Transfer archives from one repository to another, optionally upgrading the transferred data [Borg 2.0+ only]',
         description='Transfer archives from one repository to another, optionally upgrading the transferred data [Borg 2.0+ only]',
         add_help=False,
@@ -409,9 +476,9 @@ def make_parsers():
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
-    prune_parser = subparsers.add_parser(
+    prune_parser = action_parsers.add_parser(
         'prune',
-        aliases=SUBPARSER_ALIASES['prune'],
+        aliases=ACTION_ALIASES['prune'],
         help='Prune archives according to the retention policy (with Borg 1.2+, run compact afterwards to actually free space)',
         description='Prune archives according to the retention policy (with Borg 1.2+, run compact afterwards to actually free space)',
         add_help=False,
@@ -453,9 +520,9 @@ def make_parsers():
     )
     prune_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    compact_parser = subparsers.add_parser(
+    compact_parser = action_parsers.add_parser(
         'compact',
-        aliases=SUBPARSER_ALIASES['compact'],
+        aliases=ACTION_ALIASES['compact'],
         help='Compact segments to free space [Borg 1.2+, borgmatic 1.5.23+ only]',
         description='Compact segments to free space [Borg 1.2+, borgmatic 1.5.23+ only]',
         add_help=False,
@@ -489,9 +556,9 @@ def make_parsers():
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
-    create_parser = subparsers.add_parser(
+    create_parser = action_parsers.add_parser(
         'create',
-        aliases=SUBPARSER_ALIASES['create'],
+        aliases=ACTION_ALIASES['create'],
         help='Create an archive (actually perform a backup)',
         description='Create an archive (actually perform a backup)',
         add_help=False,
@@ -523,9 +590,9 @@ def make_parsers():
     )
     create_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    check_parser = subparsers.add_parser(
+    check_parser = action_parsers.add_parser(
         'check',
-        aliases=SUBPARSER_ALIASES['check'],
+        aliases=ACTION_ALIASES['check'],
         help='Check archives for consistency',
         description='Check archives for consistency',
         add_help=False,
@@ -565,9 +632,9 @@ def make_parsers():
     )
     check_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    extract_parser = subparsers.add_parser(
+    extract_parser = action_parsers.add_parser(
         'extract',
-        aliases=SUBPARSER_ALIASES['extract'],
+        aliases=ACTION_ALIASES['extract'],
         help='Extract files from a named archive to the current directory',
         description='Extract a named archive to the current directory',
         add_help=False,
@@ -611,9 +678,9 @@ def make_parsers():
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
-    config_parser = subparsers.add_parser(
+    config_parser = action_parsers.add_parser(
         'config',
-        aliases=SUBPARSER_ALIASES['config'],
+        aliases=ACTION_ALIASES['config'],
         help='Perform configuration file related operations',
         description='Perform configuration file related operations',
         add_help=False,
@@ -622,15 +689,14 @@ def make_parsers():
     config_group = config_parser.add_argument_group('config arguments')
     config_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    config_subparsers = config_parser.add_subparsers(
-        title='config subcommands',
-        description='Valid subcommands for config',
+    config_parsers = config_parser.add_subparsers(
+        title='config sub-actions',
+        description='Valid sub-actions for config',
         help='Additional help',
     )
 
-    config_bootstrap_parser = config_subparsers.add_parser(
+    config_bootstrap_parser = config_parsers.add_parser(
         'bootstrap',
-        aliases=SUBPARSER_ALIASES['config_bootstrap'],
         help='Extract the config files used to create a borgmatic repository',
         description='Extract config files that were used to create a borgmatic repository during the "create" action',
         add_help=False,
@@ -676,9 +742,9 @@ def make_parsers():
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
-    export_tar_parser = subparsers.add_parser(
+    export_tar_parser = action_parsers.add_parser(
         'export-tar',
-        aliases=SUBPARSER_ALIASES['export-tar'],
+        aliases=ACTION_ALIASES['export-tar'],
         help='Export an archive to a tar-formatted file or stream',
         description='Export an archive to a tar-formatted file or stream',
         add_help=False,
@@ -722,9 +788,9 @@ def make_parsers():
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
-    mount_parser = subparsers.add_parser(
+    mount_parser = action_parsers.add_parser(
         'mount',
-        aliases=SUBPARSER_ALIASES['mount'],
+        aliases=ACTION_ALIASES['mount'],
         help='Mount files from a named archive as a FUSE filesystem',
         description='Mount a named archive as a FUSE filesystem',
         add_help=False,
@@ -787,9 +853,9 @@ def make_parsers():
     mount_group.add_argument('--options', dest='options', help='Extra Borg mount options')
     mount_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    umount_parser = subparsers.add_parser(
+    umount_parser = action_parsers.add_parser(
         'umount',
-        aliases=SUBPARSER_ALIASES['umount'],
+        aliases=ACTION_ALIASES['umount'],
         help='Unmount a FUSE filesystem that was mounted with "borgmatic mount"',
         description='Unmount a mounted FUSE filesystem',
         add_help=False,
@@ -804,9 +870,9 @@ def make_parsers():
     )
     umount_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    restore_parser = subparsers.add_parser(
+    restore_parser = action_parsers.add_parser(
         'restore',
-        aliases=SUBPARSER_ALIASES['restore'],
+        aliases=ACTION_ALIASES['restore'],
         help='Restore database dumps from a named archive',
         description='Restore database dumps from a named archive. (To extract files instead, use "borgmatic extract".)',
         add_help=False,
@@ -837,9 +903,9 @@ def make_parsers():
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
-    rlist_parser = subparsers.add_parser(
+    rlist_parser = action_parsers.add_parser(
         'rlist',
-        aliases=SUBPARSER_ALIASES['rlist'],
+        aliases=ACTION_ALIASES['rlist'],
         help='List repository',
         description='List the archives in a repository',
         add_help=False,
@@ -897,9 +963,9 @@ def make_parsers():
     )
     rlist_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    list_parser = subparsers.add_parser(
+    list_parser = action_parsers.add_parser(
         'list',
-        aliases=SUBPARSER_ALIASES['list'],
+        aliases=ACTION_ALIASES['list'],
         help='List archive',
         description='List the files in an archive or search for a file across archives',
         add_help=False,
@@ -970,9 +1036,9 @@ def make_parsers():
     )
     list_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    rinfo_parser = subparsers.add_parser(
+    rinfo_parser = action_parsers.add_parser(
         'rinfo',
-        aliases=SUBPARSER_ALIASES['rinfo'],
+        aliases=ACTION_ALIASES['rinfo'],
         help='Show repository summary information such as disk space used',
         description='Show repository summary information such as disk space used',
         add_help=False,
@@ -987,9 +1053,9 @@ def make_parsers():
     )
     rinfo_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    info_parser = subparsers.add_parser(
+    info_parser = action_parsers.add_parser(
         'info',
-        aliases=SUBPARSER_ALIASES['info'],
+        aliases=ACTION_ALIASES['info'],
         help='Show archive summary information such as disk space used',
         description='Show archive summary information such as disk space used',
         add_help=False,
@@ -1048,9 +1114,9 @@ def make_parsers():
     )
     info_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    break_lock_parser = subparsers.add_parser(
+    break_lock_parser = action_parsers.add_parser(
         'break-lock',
-        aliases=SUBPARSER_ALIASES['break-lock'],
+        aliases=ACTION_ALIASES['break-lock'],
         help='Break the repository and cache locks left behind by Borg aborting',
         description='Break Borg repository and cache locks left behind by Borg aborting',
         add_help=False,
@@ -1064,9 +1130,9 @@ def make_parsers():
         '-h', '--help', action='help', help='Show this help message and exit'
     )
 
-    borg_parser = subparsers.add_parser(
+    borg_parser = action_parsers.add_parser(
         'borg',
-        aliases=SUBPARSER_ALIASES['borg'],
+        aliases=ACTION_ALIASES['borg'],
         help='Run an arbitrary Borg command',
         description="Run an arbitrary Borg command based on borgmatic's configuration",
         add_help=False,
@@ -1086,42 +1152,21 @@ def make_parsers():
     )
     borg_group.add_argument('-h', '--help', action='help', help='Show this help message and exit')
 
-    merged_subparsers = merge_subparsers(subparsers, config_subparsers)
-
-    return top_level_parser, merged_subparsers
-
-
-def merge_subparsers(*subparsers):
-    '''
-    Merge multiple subparsers into a single subparser.
-    '''
-    merged_subparsers = argparse._SubParsersAction(
-        None, None, metavar=None, dest='merged', parser_class=None
-    )
-
-    for subparser in subparsers:
-        for name, subparser in subparser.choices.items():
-            merged_subparsers._name_parser_map[name] = subparser
-
-    return merged_subparsers
+    return top_level_parser, action_parsers
 
 
 def parse_arguments(*unparsed_arguments):
     '''
     Given command-line arguments with which this script was invoked, parse the arguments and return
-    them as a dict mapping from subparser name (or "global") to an argparse.Namespace instance.
+    them as a dict mapping from action name (or "global") to an argparse.Namespace instance.
     '''
-    top_level_parser, subparsers = make_parsers()
+    top_level_parser, action_parsers = make_parsers()
 
-    arguments, remaining_arguments = parse_subparser_arguments(
-        unparsed_arguments, subparsers.choices
+    arguments, remaining_arguments = parse_arguments_for_actions(
+        unparsed_arguments, action_parsers.choices
     )
 
-    if (
-        'bootstrap' in arguments.keys()
-        and 'config' in arguments.keys()
-        and len(arguments.keys()) > 2
-    ):
+    if 'bootstrap' in arguments.keys() and len(arguments.keys()) > 1:
         raise ValueError(
             'The bootstrap action cannot be combined with other actions. Please run it separately.'
         )
diff --git a/borgmatic/commands/borgmatic.py b/borgmatic/commands/borgmatic.py
index c670291..babfba0 100644
--- a/borgmatic/commands/borgmatic.py
+++ b/borgmatic/commands/borgmatic.py
@@ -621,7 +621,7 @@ def collect_configuration_run_summary_logs(configs, arguments):
             )
             yield logging.makeLogRecord(
                 dict(
-                    levelno=logging.INFO,
+                    levelno=logging.ANSWER,
                     levelname='INFO',
                     msg='Bootstrap successful',
                 )
diff --git a/borgmatic/commands/completion/actions.py b/borgmatic/commands/completion/actions.py
index 690d0a8..1f0e2f3 100644
--- a/borgmatic/commands/completion/actions.py
+++ b/borgmatic/commands/completion/actions.py
@@ -1,3 +1,6 @@
+import borgmatic.commands.arguments
+
+
 def upgrade_message(language: str, upgrade_command: str, completion_file: str):
     return f'''
 Your {language} completions script is from a different version of borgmatic than is
@@ -18,24 +21,16 @@ def available_actions(subparsers, current_action=None):
     "bootstrap" is a sub-action for "config", then "bootstrap" should be able to follow a current
     action of "config" but not "list".
     '''
-    # Make a map from action name to the names of contained sub-actions.
-    actions_to_subactions = {
-        action: tuple(
-            subaction_name
-            for group_action in subparser._subparsers._group_actions
-            for subaction_name in group_action.choices.keys()
-        )
-        for action, subparser in subparsers.choices.items()
-        if subparser._subparsers
-    }
-
-    current_subactions = actions_to_subactions.get(current_action)
+    action_to_subactions = borgmatic.commands.arguments.get_subactions_for_actions(
+        subparsers.choices
+    )
+    current_subactions = action_to_subactions.get(current_action)
 
     if current_subactions:
         return current_subactions
 
     all_subactions = set(
-        subaction for subactions in actions_to_subactions.values() for subaction in subactions
+        subaction for subactions in action_to_subactions.values() for subaction in subactions
     )
 
     return tuple(action for action in subparsers.choices.keys() if action not in all_subactions)
diff --git a/tests/integration/commands/test_arguments.py b/tests/integration/commands/test_arguments.py
index 60fe884..b2b0384 100644
--- a/tests/integration/commands/test_arguments.py
+++ b/tests/integration/commands/test_arguments.py
@@ -1,5 +1,3 @@
-import argparse
-
 import pytest
 from flexmock import flexmock
 
@@ -534,24 +532,62 @@ def test_parse_arguments_extract_with_check_only_extract_does_not_raise():
     module.parse_arguments('extract', '--archive', 'name', 'check', '--only', 'extract')
 
 
-def test_merging_two_subparser_collections_merges_their_choices():
-    top_level_parser = argparse.ArgumentParser()
+def test_parse_arguments_bootstrap_without_config_errors():
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(['default'])
 
-    subparsers = top_level_parser.add_subparsers()
-    subparser1 = subparsers.add_parser('subparser1')
+    with pytest.raises(SystemExit) as exit:
+        module.parse_arguments('bootstrap')
 
-    subparser2 = subparsers.add_parser('subparser2')
-    subsubparsers = subparser2.add_subparsers()
-    subsubparser1 = subsubparsers.add_parser('subsubparser1')
+    assert exit.value.code == 2
 
-    merged_subparsers = argparse._SubParsersAction(
-        None, None, metavar=None, dest='merged', parser_class=None
-    )
 
-    merged_subparsers = module.merge_subparsers(subparsers, subsubparsers)
+def test_parse_arguments_config_with_no_subaction_errors():
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(['default'])
 
-    assert merged_subparsers.choices == {
-        'subparser1': subparser1,
-        'subparser2': subparser2,
-        'subsubparser1': subsubparser1,
-    }
+    with pytest.raises(ValueError):
+        module.parse_arguments('config')
+
+
+def test_parse_arguments_config_with_help_shows_config_help(capsys):
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(['default'])
+
+    with pytest.raises(SystemExit) as exit:
+        module.parse_arguments('config', '--help')
+
+    assert exit.value.code == 0
+    captured = capsys.readouterr()
+    assert 'global arguments:' not in captured.out
+    assert 'config arguments:' in captured.out
+    assert 'config sub-actions:' in captured.out
+
+
+def test_parse_arguments_config_with_subaction_but_missing_flags_errors(capsys):
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(['default'])
+
+    with pytest.raises(SystemExit) as exit:
+        module.parse_arguments('config', 'bootstrap')
+
+    assert exit.value.code == 2
+
+
+def test_parse_arguments_config_with_subaction_and_help_shows_subaction_help(capsys):
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(['default'])
+
+    with pytest.raises(SystemExit) as exit:
+        module.parse_arguments('config', 'bootstrap', '--help')
+
+    assert exit.value.code == 0
+    captured = capsys.readouterr()
+    assert 'config bootstrap arguments:' in captured.out
+
+
+def test_parse_arguments_config_with_subaction_and_required_flags_does_not_raise(capsys):
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(['default'])
+
+    module.parse_arguments('config', 'bootstrap', '--repository', 'repo.borg')
+
+
+def test_parse_arguments_config_with_subaction_and_global_flags_does_not_raise(capsys):
+    flexmock(module.collect).should_receive('get_default_config_paths').and_return(['default'])
+
+    module.parse_arguments('--verbosity', '1', 'config', 'bootstrap', '--repository', 'repo.borg')
diff --git a/tests/unit/commands/test_arguments.py b/tests/unit/commands/test_arguments.py
index ef8fd1e..3c32a7f 100644
--- a/tests/unit/commands/test_arguments.py
+++ b/tests/unit/commands/test_arguments.py
@@ -6,175 +6,128 @@ from flexmock import flexmock
 from borgmatic.commands import arguments as module
 
 
-def test_parse_subparser_arguments_consumes_subparser_arguments_before_subparser_name():
-    action_namespace = flexmock(foo=True)
-    subparsers = {
-        'action': flexmock(parse_known_args=lambda arguments: (action_namespace, ['action'])),
-        'other': flexmock(),
-    }
+def test_get_subaction_parsers_with_no_subactions_returns_empty_result():
+    assert module.get_subaction_parsers(flexmock(_subparsers=None)) == {}
 
-    arguments, remaining_arguments = module.parse_subparser_arguments(
-        ('--foo', 'true', 'action'), subparsers
+
+def test_get_subaction_parsers_with_subactions_returns_one_entry_per_subaction():
+    foo_parser = flexmock()
+    bar_parser = flexmock()
+    baz_parser = flexmock()
+
+    assert module.get_subaction_parsers(
+        flexmock(
+            _subparsers=flexmock(
+                _group_actions=(
+                    flexmock(choices={'foo': foo_parser, 'bar': bar_parser}),
+                    flexmock(choices={'baz': baz_parser}),
+                )
+            )
+        )
+    ) == {'foo': foo_parser, 'bar': bar_parser, 'baz': baz_parser}
+
+
+def test_get_subactions_for_actions_with_no_subactions_returns_empty_result():
+    assert module.get_subactions_for_actions({'action': flexmock(_subparsers=None)}) == {}
+
+
+def test_get_subactions_for_actions_with_subactions_returns_one_entry_per_action():
+    assert module.get_subactions_for_actions(
+        {
+            'action': flexmock(
+                _subparsers=flexmock(
+                    _group_actions=(
+                        flexmock(choices={'foo': flexmock(), 'bar': flexmock()}),
+                        flexmock(choices={'baz': flexmock()}),
+                    )
+                )
+            ),
+            'other': flexmock(
+                _subparsers=flexmock(_group_actions=(flexmock(choices={'quux': flexmock()}),))
+            ),
+        }
+    ) == {'action': ('foo', 'bar', 'baz'), 'other': ('quux',)}
+
+
+def test_omit_values_colliding_with_action_names_drops_action_names_that_have__been_parsed_as_values():
+    assert module.omit_values_colliding_with_action_names(
+        ('check', '--only', 'extract', '--some-list', 'borg'),
+        {'check': flexmock(only='extract', some_list=['borg'])},
+    ) == ('check', '--only', '--some-list')
+
+
+def test_parse_and_record_action_arguments_without_action_name_leaves_arguments_untouched():
+    unparsed_arguments = ('--foo', '--bar')
+    flexmock(module).should_receive('omit_values_colliding_with_action_names').and_return(
+        unparsed_arguments
     )
 
-    assert arguments == {'action': action_namespace}
-    assert remaining_arguments == []
-
-
-def test_parse_subparser_arguments_consumes_subparser_arguments_after_subparser_name():
-    action_namespace = flexmock(foo=True)
-    subparsers = {
-        'action': flexmock(parse_known_args=lambda arguments: (action_namespace, ['action'])),
-        'other': flexmock(),
-    }
-
-    arguments, remaining_arguments = module.parse_subparser_arguments(
-        ('action', '--foo', 'true'), subparsers
+    assert (
+        module.parse_and_record_action_arguments(
+            unparsed_arguments, flexmock(), flexmock(), 'action'
+        )
+        == unparsed_arguments
     )
 
-    assert arguments == {'action': action_namespace}
-    assert remaining_arguments == []
 
-
-def test_parse_subparser_arguments_consumes_subparser_arguments_with_alias():
-    action_namespace = flexmock(foo=True)
-    action_subparser = flexmock(parse_known_args=lambda arguments: (action_namespace, ['action']))
-    subparsers = {
-        'action': action_subparser,
-        '-a': action_subparser,
-        'other': flexmock(),
-        '-o': flexmock(),
-    }
-    flexmock(module).SUBPARSER_ALIASES = {'action': ['-a'], 'other': ['-o']}
-
-    arguments, remaining_arguments = module.parse_subparser_arguments(
-        ('-a', '--foo', 'true'), subparsers
+def test_parse_and_record_action_arguments_updates_parsed_arguments_and_returns_remaining():
+    unparsed_arguments = ('action', '--foo', '--bar', '--verbosity', '1')
+    other_parsed_arguments = flexmock()
+    parsed_arguments = {'other': other_parsed_arguments}
+    action_parsed_arguments = flexmock()
+    flexmock(module).should_receive('omit_values_colliding_with_action_names').and_return(
+        unparsed_arguments
+    )
+    action_parser = flexmock()
+    flexmock(action_parser).should_receive('parse_known_args').and_return(
+        action_parsed_arguments, ('action', '--verbosity', '1')
     )
 
-    assert arguments == {'action': action_namespace}
-    assert remaining_arguments == []
+    assert module.parse_and_record_action_arguments(
+        unparsed_arguments, parsed_arguments, action_parser, 'action'
+    ) == ('--verbosity', '1')
+    assert parsed_arguments == {'other': other_parsed_arguments, 'action': action_parsed_arguments}
 
 
-def test_parse_subparser_arguments_consumes_multiple_subparser_arguments():
-    action_namespace = flexmock(foo=True)
-    other_namespace = flexmock(bar=3)
-    subparsers = {
-        'action': flexmock(
-            parse_known_args=lambda arguments: (action_namespace, ['action', '--bar', '3'])
-        ),
-        'other': flexmock(parse_known_args=lambda arguments: (other_namespace, [])),
-    }
-
-    arguments, remaining_arguments = module.parse_subparser_arguments(
-        ('action', '--foo', 'true', 'other', '--bar', '3'), subparsers
+def test_parse_and_record_action_arguments_with_alias_updates_canonical_parsed_arguments():
+    unparsed_arguments = ('action', '--foo', '--bar', '--verbosity', '1')
+    other_parsed_arguments = flexmock()
+    parsed_arguments = {'other': other_parsed_arguments}
+    action_parsed_arguments = flexmock()
+    flexmock(module).should_receive('omit_values_colliding_with_action_names').and_return(
+        unparsed_arguments
+    )
+    action_parser = flexmock()
+    flexmock(action_parser).should_receive('parse_known_args').and_return(
+        action_parsed_arguments, ('action', '--verbosity', '1')
     )
 
-    assert arguments == {'action': action_namespace, 'other': other_namespace}
-    assert remaining_arguments == []
+    assert module.parse_and_record_action_arguments(
+        unparsed_arguments, parsed_arguments, action_parser, 'action', canonical_name='doit'
+    ) == ('--verbosity', '1')
+    assert parsed_arguments == {'other': other_parsed_arguments, 'doit': action_parsed_arguments}
 
 
-def test_parse_subparser_arguments_respects_command_line_action_ordering():
-    other_namespace = flexmock()
-    action_namespace = flexmock(foo=True)
-    subparsers = {
-        'action': flexmock(
-            parse_known_args=lambda arguments: (action_namespace, ['action', '--foo', 'true'])
-        ),
-        'other': flexmock(parse_known_args=lambda arguments: (other_namespace, ['other'])),
-    }
-
-    arguments, remaining_arguments = module.parse_subparser_arguments(
-        ('other', '--foo', 'true', 'action'), subparsers
+def test_parse_and_record_action_arguments_with_borg_action_consumes_arguments_after_action_name():
+    unparsed_arguments = ('--verbosity', '1', 'borg', 'list')
+    parsed_arguments = {}
+    borg_parsed_arguments = flexmock(options=flexmock())
+    flexmock(module).should_receive('omit_values_colliding_with_action_names').and_return(
+        unparsed_arguments
+    )
+    borg_parser = flexmock()
+    flexmock(borg_parser).should_receive('parse_known_args').and_return(
+        borg_parsed_arguments, ('--verbosity', '1', 'borg', 'list')
     )
 
-    assert arguments == collections.OrderedDict(
-        [('other', other_namespace), ('action', action_namespace)]
-    )
-    assert remaining_arguments == []
-
-
-def test_parse_subparser_arguments_applies_default_subparsers():
-    prune_namespace = flexmock()
-    compact_namespace = flexmock()
-    create_namespace = flexmock(progress=True)
-    check_namespace = flexmock()
-    subparsers = {
-        'prune': flexmock(
-            parse_known_args=lambda arguments: (prune_namespace, ['prune', '--progress'])
-        ),
-        'compact': flexmock(parse_known_args=lambda arguments: (compact_namespace, [])),
-        'create': flexmock(parse_known_args=lambda arguments: (create_namespace, [])),
-        'check': flexmock(parse_known_args=lambda arguments: (check_namespace, [])),
-        'other': flexmock(),
-    }
-
-    arguments, remaining_arguments = module.parse_subparser_arguments(('--progress'), subparsers)
-
-    assert arguments == {
-        'prune': prune_namespace,
-        'compact': compact_namespace,
-        'create': create_namespace,
-        'check': check_namespace,
-    }
-    assert remaining_arguments == []
-
-
-def test_parse_subparser_arguments_passes_through_unknown_arguments_before_subparser_name():
-    action_namespace = flexmock()
-    subparsers = {
-        'action': flexmock(
-            parse_known_args=lambda arguments: (action_namespace, ['action', '--verbosity', 'lots'])
-        ),
-        'other': flexmock(),
-    }
-
-    arguments, remaining_arguments = module.parse_subparser_arguments(
-        ('--verbosity', 'lots', 'action'), subparsers
-    )
-
-    assert arguments == {'action': action_namespace}
-    assert remaining_arguments == ['--verbosity', 'lots']
-
-
-def test_parse_subparser_arguments_passes_through_unknown_arguments_after_subparser_name():
-    action_namespace = flexmock()
-    subparsers = {
-        'action': flexmock(
-            parse_known_args=lambda arguments: (action_namespace, ['action', '--verbosity', 'lots'])
-        ),
-        'other': flexmock(),
-    }
-
-    arguments, remaining_arguments = module.parse_subparser_arguments(
-        ('action', '--verbosity', 'lots'), subparsers
-    )
-
-    assert arguments == {'action': action_namespace}
-    assert remaining_arguments == ['--verbosity', 'lots']
-
-
-def test_parse_subparser_arguments_parses_borg_options_and_skips_other_subparsers():
-    action_namespace = flexmock(options=[])
-    subparsers = {
-        'borg': flexmock(parse_known_args=lambda arguments: (action_namespace, ['borg', 'list'])),
-        'list': flexmock(),
-    }
-
-    arguments, remaining_arguments = module.parse_subparser_arguments(('borg', 'list'), subparsers)
-
-    assert arguments == {'borg': action_namespace}
-    assert arguments['borg'].options == ['list']
-    assert remaining_arguments == []
-
-
-def test_parse_subparser_arguments_raises_error_when_no_subparser_is_specified():
-    action_namespace = flexmock(options=[])
-    subparsers = {
-        'config': flexmock(parse_known_args=lambda arguments: (action_namespace, ['config'])),
-    }
-
-    with pytest.raises(ValueError):
-        module.parse_subparser_arguments(('config',), subparsers)
+    assert module.parse_and_record_action_arguments(
+        unparsed_arguments,
+        parsed_arguments,
+        borg_parser,
+        'borg',
+    ) == ('--verbosity', '1')
+    assert parsed_arguments == {'borg': borg_parsed_arguments}
+    assert borg_parsed_arguments.options == ('list',)
 
 
 @pytest.mark.parametrize(
@@ -187,9 +140,7 @@ def test_parse_subparser_arguments_raises_error_when_no_subparser_is_specified()
                 ('prune', 'check', 'list', '--test-flag'),
                 ('prune', 'check', 'extract', '--test-flag'),
             ),
-            [
-                '--test-flag',
-            ],
+            ('--test-flag',),
         ),
         (
             (
@@ -198,12 +149,241 @@ def test_parse_subparser_arguments_raises_error_when_no_subparser_is_specified()
                 ('prune', 'check', 'list'),
                 ('prune', 'check', 'extract'),
             ),
-            [],
+            (),
         ),
-        ((), []),
+        ((), ()),
     ],
 )
-def test_get_unparsable_arguments_returns_remaining_arguments_that_no_subparser_can_parse(
+def test_get_unparsable_arguments_returns_remaining_arguments_that_no_action_can_parse(
     arguments, expected
 ):
     assert module.get_unparsable_arguments(arguments) == expected
+
+
+def test_parse_arguments_for_actions_consumes_action_arguments_before_action_name():
+    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: action_namespace}
+        )
+    ).and_return(())
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(())
+    action_parsers = {'action': flexmock(), 'other': flexmock()}
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('--foo', 'true', 'action'), action_parsers
+    )
+
+    assert arguments == {'action': action_namespace}
+    assert remaining_arguments == ()
+
+
+def test_parse_arguments_for_actions_consumes_action_arguments_after_action_name():
+    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: action_namespace}
+        )
+    ).and_return(())
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(())
+    action_parsers = {'action': flexmock(), 'other': flexmock()}
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('action', '--foo', 'true'), action_parsers
+    )
+
+    assert arguments == {'action': action_namespace}
+    assert remaining_arguments == ()
+
+
+def test_parse_arguments_for_actions_consumes_action_arguments_with_alias():
+    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(
+            {canonical or action: action_namespace}
+        )
+    ).and_return(())
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(())
+    action_parsers = {
+        'action': flexmock(),
+        '-a': flexmock(),
+        'other': flexmock(),
+        '-o': flexmock(),
+    }
+    flexmock(module).ACTION_ALIASES = {'action': ['-a'], 'other': ['-o']}
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('-a', '--foo', 'true'), action_parsers
+    )
+
+    assert arguments == {'action': action_namespace}
+    assert remaining_arguments == ()
+
+
+def test_parse_arguments_for_actions_consumes_multiple_action_arguments():
+    action_namespace = flexmock(foo=True)
+    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}
+        )
+    ).and_return(('other', '--bar', '3')).and_return('action', '--foo', 'true')
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(())
+    action_parsers = {
+        'action': flexmock(),
+        'other': flexmock(),
+    }
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('action', '--foo', 'true', 'other', '--bar', '3'), action_parsers
+    )
+
+    assert arguments == {'action': action_namespace, 'other': other_namespace}
+    assert remaining_arguments == ()
+
+
+def test_parse_arguments_for_actions_respects_command_line_action_ordering():
+    other_namespace = flexmock()
+    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}
+        )
+    ).and_return(('action',)).and_return(('other', '--foo', 'true'))
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(())
+    action_parsers = {
+        'action': flexmock(),
+        'other': flexmock(),
+    }
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('other', '--foo', 'true', 'action'), action_parsers
+    )
+
+    assert arguments == collections.OrderedDict(
+        [('other', other_namespace), ('action', action_namespace)]
+    )
+    assert remaining_arguments == ()
+
+
+def test_parse_arguments_for_actions_applies_default_action_parsers():
+    namespaces = {
+        'prune': flexmock(),
+        'compact': flexmock(),
+        'create': flexmock(progress=True),
+        'check': 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: namespaces.get(action)}
+        )
+    ).and_return(())
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(())
+    action_parsers = {
+        'prune': flexmock(),
+        'compact': flexmock(),
+        'create': flexmock(),
+        'check': flexmock(),
+        'other': flexmock(),
+    }
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('--progress'), action_parsers
+    )
+
+    assert arguments == namespaces
+    assert remaining_arguments == ()
+
+
+def test_parse_arguments_for_actions_passes_through_unknown_arguments_before_action_name():
+    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}
+        )
+    ).and_return(('--verbosity', 'lots'))
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(('--verbosity', 'lots'))
+    action_parsers = {
+        'action': flexmock(),
+        'other': flexmock(),
+    }
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('--verbosity', 'lots', 'action'), action_parsers
+    )
+
+    assert arguments == {'action': action_namespace}
+    assert remaining_arguments == ('--verbosity', 'lots')
+
+
+def test_parse_arguments_for_actions_passes_through_unknown_arguments_after_action_name():
+    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}
+        )
+    ).and_return(('--verbosity', 'lots'))
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(('--verbosity', 'lots'))
+    action_parsers = {
+        'action': flexmock(),
+        'other': flexmock(),
+    }
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('action', '--verbosity', 'lots'), action_parsers
+    )
+
+    assert arguments == {'action': action_namespace}
+    assert remaining_arguments == ('--verbosity', 'lots')
+
+
+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}
+        )
+    ).and_return(())
+    flexmock(module).should_receive('get_subactions_for_actions').and_return({})
+    flexmock(module).should_receive('get_unparsable_arguments').and_return(())
+    action_parsers = {
+        'borg': flexmock(),
+        'list': flexmock(),
+    }
+
+    arguments, remaining_arguments = module.parse_arguments_for_actions(
+        ('borg', 'list'), action_parsers
+    )
+
+    assert arguments == {'borg': action_namespace}
+    assert remaining_arguments == ()
+
+
+def test_parse_arguments_for_actions_raises_error_when_no_action_is_specified():
+    flexmock(module).should_receive('get_subaction_parsers').and_return({'bootstrap': [flexmock()]})
+    flexmock(module).should_receive('parse_and_record_action_arguments').and_return(flexmock())
+    flexmock(module).should_receive('get_subactions_for_actions').and_return(
+        {'config': ['bootstrap']}
+    )
+    action_parsers = {'config': flexmock()}
+
+    with pytest.raises(ValueError):
+        module.parse_arguments_for_actions(('config',), action_parsers)
diff --git a/tests/unit/commands/test_borgmatic.py b/tests/unit/commands/test_borgmatic.py
index 60fb756..5ac0632 100644
--- a/tests/unit/commands/test_borgmatic.py
+++ b/tests/unit/commands/test_borgmatic.py
@@ -1013,7 +1013,7 @@ def test_collect_configuration_run_summary_logs_info_for_success_with_bootstrap(
     logs = tuple(
         module.collect_configuration_run_summary_logs({'test.yaml': {}}, arguments=arguments)
     )
-    assert {log.levelno for log in logs} == {logging.INFO}
+    assert {log.levelno for log in logs} == {logging.ANSWER}
 
 
 def test_collect_configuration_run_summary_logs_error_on_bootstrap_failure():