def METHOD_NAME(
        *,
        args: argparse.Namespace,
        root: str,
) -> bool:
    '''Ensures that schema.sql and dao_schema.sql are not modified together.'''
    merge_base = subprocess.run(
        [
            '/usr/bin/git',
            'rev-parse',
            '--abbrev-ref',
            '--symbolic-full-name',
            '@{u}',
        ],
        check=False,
        universal_newlines=True,
        stdout=subprocess.PIPE,
        cwd=root,
    ).stdout.strip() or 'origin/main'
    modified_files = set(
        filename.decode('utf-8') for filename in subprocess.run(
            [
                '/usr/bin/git',
                '--no-pager',
                'diff',
                '-z',
                '--name-only',
                merge_base,
            ],
            check=True,
            stdout=subprocess.PIPE,
            cwd=root).stdout.strip(b'\x00').split(b'\x00'))
    schema_sql_filename = 'frontend/database/schema.sql'
    dao_schema_sql_filename = 'frontend/database/dao_schema.sql'
    schema_sql_modified = schema_sql_filename in modified_files
    dao_schema_sql_modified = dao_schema_sql_filename in modified_files
    if not schema_sql_modified and not dao_schema_sql_modified:
        # Neither file got modified, all's good.
        return True
    if schema_sql_modified and dao_schema_sql_modified:
        # Welp, both files got modified, this is bad.
        print((f'{git_tools.COLORS.FAIL}{schema_sql_filename!r} and '
               f'{dao_schema_sql_filename!r} cannot be modified in '
               f'the same commit.{git_tools.COLORS.NORMAL}'),
              file=sys.stderr)
        return False
    if schema_sql_modified:
        # This is okay. Only the schema.sql file was modified. The rest of this
        # script will validate whether it has the correct contents.
        return True
    schema_sql = git_tools.file_contents(args, root, schema_sql_filename)
    dao_schema_sql = git_tools.file_contents(args, root,
                                             dao_schema_sql_filename)
    if schema_sql != dao_schema_sql:
        print((f'{git_tools.COLORS.FAIL}{dao_schema_sql_filename!r} can only '
               f'have the same contents as {schema_sql_filename!r}.'
               f'{git_tools.COLORS.NORMAL}'),
              file=sys.stderr)
        return False
    return True