# Buggy code
def load_list_of_tasks(
    ds,
    play,
    block=None,
    role=None,
    task_include=None,
    use_handlers=False,
    variable_manager=None,
    loader=None,
):
    """
    Given a list of task datastructures (parsed from YAML),
    return a list of Task() or TaskInclude() objects.
    """

    # we import here to prevent a circular dependency with imports
    from ansible.playbook.block import Block
    from ansible.playbook.handler import Handler
    from ansible.playbook.task import Task
    from ansible.playbook.task_include import TaskInclude
    from ansible.playbook.role_include import IncludeRole
    from ansible.playbook.handler_task_include import HandlerTaskInclude
    from ansible.template import Templar

    assert isinstance(ds, list)

    task_list = []
    for task_ds in ds:
        assert isinstance(task_ds, dict)

        if "block" in task_ds:
            t = Block.load(
                task_ds,
                play=play,
                parent_block=block,
                role=role,
                task_include=task_include,
                use_handlers=use_handlers,
                variable_manager=variable_manager,
                loader=loader,
            )
            task_list.append(t)
        else:
            if "include" in task_ds:
                if use_handlers:
                    include_class = HandlerTaskInclude
                else:
                    include_class = TaskInclude

                t = include_class.load(
                    task_ds,
                    block=block,
                    role=role,
                    task_include=None,
                    variable_manager=variable_manager,
                    loader=loader,
                )

                all_vars = variable_manager.get_vars(loader=loader, play=play, task=t)
                templar = Templar(loader=loader, variables=all_vars)

                # check to see if this include is dynamic or static:
                # 1. the user has set the 'static' option to false or true
                # 2. one of the appropriate config options was set
                if t.static is not None:
                    is_static = t.static
                else:
                    is_static = (
                        C.DEFAULT_TASK_INCLUDES_STATIC
                        or (use_handlers and C.DEFAULT_HANDLER_INCLUDES_STATIC)
                        or (
                            not templar._contains_vars(t.args["_raw_params"])
                            and t.all_parents_static()
                            and not t.loop
                        )
                    )

                if is_static:
                    if t.loop is not None:
                        raise AnsibleParserError(
                            "You cannot use 'static' on an include with a loop",
                            obj=task_ds,
                        )

                    # we set a flag to indicate this include was static
                    t.statically_loaded = True

                    # handle relative includes by walking up the list of parent include
                    # tasks and checking the relative result to see if it exists
                    parent_include = block
                    cumulative_path = None

                    found = False
                    subdir = "tasks"
                    if use_handlers:
                        subdir = "handlers"
                    while parent_include is not None:
                        if not isinstance(parent_include, TaskInclude):
                            parent_include = parent_include._parent
                            continue
                        parent_include_dir = os.path.dirname(
                            templar.template(parent_include.args.get("_raw_params"))
                        )
                        if cumulative_path is None:
                            cumulative_path = parent_include_dir
                        elif not os.path.isabs(cumulative_path):
                            cumulative_path = os.path.join(
                                parent_include_dir, cumulative_path
                            )
                        include_target = templar.template(t.args["_raw_params"])
                        if t._role:
                            new_basedir = os.path.join(
                                t._role._role_path, subdir, cumulative_path
                            )
                            include_file = loader.path_dwim_relative(
                                new_basedir, subdir, include_target
                            )
                        else:
                            include_file = loader.path_dwim_relative(
                                loader.get_basedir(), cumulative_path, include_target
                            )

                        if os.path.exists(include_file):
                            found = True
                            break
                        else:
                            parent_include = parent_include._parent

                    if not found:
                        try:
                            include_target = templar.template(t.args["_raw_params"])
                        except AnsibleUndefinedVariable:
                            raise AnsibleParserError(
                                "Error when evaluating variable in include name: %s.\n\n"
                                "When using static includes, ensure that any variables used in their names are defined in vars/vars_files\n"
                                "or extra-vars passed in from the command line. Static includes cannot use variables from inventory\n"
                                "sources like group or host vars."
                                % t.args["_raw_params"],
                                obj=task_ds,
                                suppress_extended_error=True,
                            )
                        if t._role:
                            include_file = loader.path_dwim_relative(
                                t._role._role_path, subdir, include_target
                            )
                        else:
                            include_file = loader.path_dwim(include_target)

                    try:
                        data = loader.load_from_file(include_file)
                        if data is None:
                            return []
                        elif not isinstance(data, list):
                            raise AnsibleParserError(
                                "included task files must contain a list of tasks",
                                obj=data,
                            )

                        # since we can't send callbacks here, we display a message directly in
                        # the same fashion used by the on_include callback. We also do it here,
                        # because the recursive nature of helper methods means we may be loading
                        # nested includes, and we want the include order printed correctly
                        display.vv("statically included: %s" % include_file)
                    except AnsibleFileNotFound:
                        if (
                            t.static
                            or C.DEFAULT_TASK_INCLUDES_STATIC
                            or C.DEFAULT_HANDLER_INCLUDES_STATIC
                            and use_handlers
                        ):
                            raise
                        display.deprecated(
                            "Included file '%s' not found, however since this include is not "
                            "explicitly marked as 'static: yes', we will try and include it dynamically "
                            "later. In the future, this will be an error unless 'static: no' is used "
                            "on the include task. If you do not want missing includes to be considered "
                            "dynamic, use 'static: yes' on the include or set the global ansible.cfg "
                            "options to make all inclues static for tasks and/or handlers"
                            % include_file,
                        )
                        task_list.append(t)
                        continue

                    ti_copy = t.copy(exclude_parent=True)
                    ti_copy._parent = block
                    included_blocks = load_list_of_blocks(
                        data,
                        play=play,
                        parent_block=None,
                        task_include=ti_copy,
                        role=role,
                        use_handlers=use_handlers,
                        loader=loader,
                        variable_manager=variable_manager,
                    )

                    # pop tags out of the include args, if they were specified there, and assign
                    # them to the include. If the include already had tags specified, we raise an
                    # error so that users know not to specify them both ways
                    tags = ti_copy.vars.pop("tags", [])
                    if isinstance(tags, string_types):
                        tags = tags.split(",")

                    if len(tags) > 0:
                        if len(ti_copy.tags) > 0:
                            raise AnsibleParserError(
                                "Include tasks should not specify tags in more than one way (both via args and directly on the task). "
                                "Mixing styles in which tags are specified is prohibited for whole import hierarchy, not only for single import statement",
                                obj=task_ds,
                                suppress_extended_error=True,
                            )
                        display.deprecated(
                            "You should not specify tags in the include parameters. All tags should be specified using the task-level option"
                        )
                    else:
                        tags = ti_copy.tags[:]

                    # now we extend the tags on each of the included blocks
                    for b in included_blocks:
                        b.tags = list(set(b.tags).union(tags))
                    # END FIXME

                    # FIXME: handlers shouldn't need this special handling, but do
                    #        right now because they don't iterate blocks correctly
                    if use_handlers:
                        for b in included_blocks:
                            task_list.extend(b.block)
                    else:
                        task_list.extend(included_blocks)
                else:
                    task_list.append(t)

            elif "include_role" in task_ds:
                ir = IncludeRole.load(
                    task_ds,
                    block=block,
                    role=role,
                    task_include=None,
                    variable_manager=variable_manager,
                    loader=loader,
                )

                #   1. the user has set the 'static' option to false or true
                #   2. one of the appropriate config options was set
                if ir.static is not None:
                    is_static = ir.static
                else:
                    display.debug("Determine if include_role is static")
                    # Check to see if this include is dynamic or static:
                    all_vars = variable_manager.get_vars(
                        loader=loader, play=play, task=ir
                    )
                    templar = Templar(loader=loader, variables=all_vars)
                    needs_templating = False
                    for param in ir.args:
                        if templar._contains_vars(ir.args[param]):
                            if not templar.is_template(ir.args[param]):
                                needs_templating = True
                                break
                    is_static = (
                        C.DEFAULT_TASK_INCLUDES_STATIC
                        or (use_handlers and C.DEFAULT_HANDLER_INCLUDES_STATIC)
                        or (
                            not needs_templating
                            and ir.all_parents_static()
                            and not ir.loop
                        )
                    )
                    display.debug(
                        "Determined that if include_role static is %s" % str(is_static)
                    )

                if is_static:
                    # uses compiled list from object
                    t = task_list.extend(
                        ir.get_block_list(
                            variable_manager=variable_manager, loader=loader
                        )
                    )
                else:
                    # passes task object itself for latter generation of list
                    t = task_list.append(ir)
            else:
                if use_handlers:
                    t = Handler.load(
                        task_ds,
                        block=block,
                        role=role,
                        task_include=task_include,
                        variable_manager=variable_manager,
                        loader=loader,
                    )
                else:
                    t = Task.load(
                        task_ds,
                        block=block,
                        role=role,
                        task_include=task_include,
                        variable_manager=variable_manager,
                        loader=loader,
                    )

                task_list.append(t)

    return task_list


# Traceback (KeyError)
ansible-playbook -vvvv playbook.yml
No config file found; using defaults
[WARNING]: Host file not found: /etc/ansible/hosts

[WARNING]: provided hosts list is empty, only localhost is available

Loading callback plugin default of type stdout, v2.0 from /usr/local/lib/python2.7/site-packages/ansible/plugins/callback/__init__.pyc

PLAYBOOK: playbook.yml *********************************************************
1 plays in playbook.yml

PLAY [localhost] ***************************************************************

TASK [include_role] ************************************************************
task path: /Users/xxx/workspace/xxx/playbook.yml:6

TASK [handlertest : command] ***************************************************
task path: /Users/xxx/workspace/xxx/roles/handlertest/tasks/main.yml:3
Using module file /usr/local/lib/python2.7/site-packages/ansible/modules/core/commands/command.py
<127.0.0.1> ESTABLISH LOCAL CONNECTION FOR USER: xxx
<127.0.0.1> EXEC /bin/sh -c '( umask 77 &amp;&amp; mkdir -p "` echo $HOME/.ansible/tmp/ansible-tmp-1478572148.78-187995060050975 `" &amp;&amp; echo ansible-tmp-1478572148.78-187995060050975="` echo $HOME/.ansible/tmp/ansible-tmp-1478572148.78-187995060050975 `" ) &amp;&amp; sleep 0'
<127.0.0.1> PUT /var/folders/62/pqgvprd11fb4k6shw2pdzkqm0000gq/T/tmpGA2Gau TO /Users/xxx/.ansible/tmp/ansible-tmp-1478572148.78-187995060050975/command.py
<127.0.0.1> EXEC /bin/sh -c 'chmod u+x /Users/xxx/.ansible/tmp/ansible-tmp-1478572148.78-187995060050975/ /Users/xxx/.ansible/tmp/ansible-tmp-1478572148.78-187995060050975/command.py &amp;&amp; sleep 0'
<127.0.0.1> EXEC /bin/sh -c '/usr/local/opt/python/bin/python2.7 /Users/xxx/.ansible/tmp/ansible-tmp-1478572148.78-187995060050975/command.py; rm -rf "/Users/xxx/.ansible/tmp/ansible-tmp-1478572148.78-187995060050975/" > /dev/null 2>&amp;1 &amp;&amp; sleep 0'
ERROR! Unexpected Exception: HANDLER: handlertest : Some handler
the full traceback was:

Traceback (most recent call last):
File "/usr/local/bin/ansible-playbook", line 103, in <module>
exit_code = cli.run()
File "/usr/local/lib/python2.7/site-packages/ansible/cli/playbook.py", line 159, in run
results = pbex.run()
File "/usr/local/lib/python2.7/site-packages/ansible/executor/playbook_executor.py", line 154, in run
result = self._tqm.run(play=play)
File "/usr/local/lib/python2.7/site-packages/ansible/executor/task_queue_manager.py", line 282, in run
play_return = strategy.run(iterator, play_context)
File "/usr/local/lib/python2.7/site-packages/ansible/plugins/strategy/linear.py", line 278, in run
results += self._wait_on_pending_results(iterator)
File "/usr/local/lib/python2.7/site-packages/ansible/plugins/strategy/__init__.py", line 534, in _wait_on_pending_results
results = self._process_pending_results(iterator)
File "/usr/local/lib/python2.7/site-packages/ansible/plugins/strategy/__init__.py", line 399, in _process_pending_results
if original_host not in self._notified_handlers[target_handler]:
KeyError: HANDLER: handlertest : Some handler

# Fixed code
def load_list_of_tasks(
    ds,
    play,
    block=None,
    role=None,
    task_include=None,
    use_handlers=False,
    variable_manager=None,
    loader=None,
):
    """
    Given a list of task datastructures (parsed from YAML),
    return a list of Task() or TaskInclude() objects.
    """

    # we import here to prevent a circular dependency with imports
    from ansible.playbook.block import Block
    from ansible.playbook.handler import Handler
    from ansible.playbook.task import Task
    from ansible.playbook.task_include import TaskInclude
    from ansible.playbook.role_include import IncludeRole
    from ansible.playbook.handler_task_include import HandlerTaskInclude
    from ansible.template import Templar

    assert isinstance(ds, list)

    task_list = []
    for task_ds in ds:
        assert isinstance(task_ds, dict)

        if "block" in task_ds:
            t = Block.load(
                task_ds,
                play=play,
                parent_block=block,
                role=role,
                task_include=task_include,
                use_handlers=use_handlers,
                variable_manager=variable_manager,
                loader=loader,
            )
            task_list.append(t)
        else:
            if "include" in task_ds:
                if use_handlers:
                    include_class = HandlerTaskInclude
                else:
                    include_class = TaskInclude

                t = include_class.load(
                    task_ds,
                    block=block,
                    role=role,
                    task_include=None,
                    variable_manager=variable_manager,
                    loader=loader,
                )

                all_vars = variable_manager.get_vars(loader=loader, play=play, task=t)
                templar = Templar(loader=loader, variables=all_vars)

                # check to see if this include is dynamic or static:
                # 1. the user has set the 'static' option to false or true
                # 2. one of the appropriate config options was set
                if t.static is not None:
                    is_static = t.static
                else:
                    is_static = (
                        C.DEFAULT_TASK_INCLUDES_STATIC
                        or (use_handlers and C.DEFAULT_HANDLER_INCLUDES_STATIC)
                        or (
                            not templar._contains_vars(t.args["_raw_params"])
                            and t.all_parents_static()
                            and not t.loop
                        )
                    )

                if is_static:
                    if t.loop is not None:
                        raise AnsibleParserError(
                            "You cannot use 'static' on an include with a loop",
                            obj=task_ds,
                        )

                    # we set a flag to indicate this include was static
                    t.statically_loaded = True

                    # handle relative includes by walking up the list of parent include
                    # tasks and checking the relative result to see if it exists
                    parent_include = block
                    cumulative_path = None

                    found = False
                    subdir = "tasks"
                    if use_handlers:
                        subdir = "handlers"
                    while parent_include is not None:
                        if not isinstance(parent_include, TaskInclude):
                            parent_include = parent_include._parent
                            continue
                        parent_include_dir = os.path.dirname(
                            templar.template(parent_include.args.get("_raw_params"))
                        )
                        if cumulative_path is None:
                            cumulative_path = parent_include_dir
                        elif not os.path.isabs(cumulative_path):
                            cumulative_path = os.path.join(
                                parent_include_dir, cumulative_path
                            )
                        include_target = templar.template(t.args["_raw_params"])
                        if t._role:
                            new_basedir = os.path.join(
                                t._role._role_path, subdir, cumulative_path
                            )
                            include_file = loader.path_dwim_relative(
                                new_basedir, subdir, include_target
                            )
                        else:
                            include_file = loader.path_dwim_relative(
                                loader.get_basedir(), cumulative_path, include_target
                            )

                        if os.path.exists(include_file):
                            found = True
                            break
                        else:
                            parent_include = parent_include._parent

                    if not found:
                        try:
                            include_target = templar.template(t.args["_raw_params"])
                        except AnsibleUndefinedVariable:
                            raise AnsibleParserError(
                                "Error when evaluating variable in include name: %s.\n\n"
                                "When using static includes, ensure that any variables used in their names are defined in vars/vars_files\n"
                                "or extra-vars passed in from the command line. Static includes cannot use variables from inventory\n"
                                "sources like group or host vars."
                                % t.args["_raw_params"],
                                obj=task_ds,
                                suppress_extended_error=True,
                            )
                        if t._role:
                            include_file = loader.path_dwim_relative(
                                t._role._role_path, subdir, include_target
                            )
                        else:
                            include_file = loader.path_dwim(include_target)

                    try:
                        data = loader.load_from_file(include_file)
                        if data is None:
                            return []
                        elif not isinstance(data, list):
                            raise AnsibleParserError(
                                "included task files must contain a list of tasks",
                                obj=data,
                            )

                        # since we can't send callbacks here, we display a message directly in
                        # the same fashion used by the on_include callback. We also do it here,
                        # because the recursive nature of helper methods means we may be loading
                        # nested includes, and we want the include order printed correctly
                        display.vv("statically included: %s" % include_file)
                    except AnsibleFileNotFound:
                        if (
                            t.static
                            or C.DEFAULT_TASK_INCLUDES_STATIC
                            or C.DEFAULT_HANDLER_INCLUDES_STATIC
                            and use_handlers
                        ):
                            raise
                        display.deprecated(
                            "Included file '%s' not found, however since this include is not "
                            "explicitly marked as 'static: yes', we will try and include it dynamically "
                            "later. In the future, this will be an error unless 'static: no' is used "
                            "on the include task. If you do not want missing includes to be considered "
                            "dynamic, use 'static: yes' on the include or set the global ansible.cfg "
                            "options to make all inclues static for tasks and/or handlers"
                            % include_file,
                        )
                        task_list.append(t)
                        continue

                    ti_copy = t.copy(exclude_parent=True)
                    ti_copy._parent = block
                    included_blocks = load_list_of_blocks(
                        data,
                        play=play,
                        parent_block=None,
                        task_include=ti_copy,
                        role=role,
                        use_handlers=use_handlers,
                        loader=loader,
                        variable_manager=variable_manager,
                    )

                    # pop tags out of the include args, if they were specified there, and assign
                    # them to the include. If the include already had tags specified, we raise an
                    # error so that users know not to specify them both ways
                    tags = ti_copy.vars.pop("tags", [])
                    if isinstance(tags, string_types):
                        tags = tags.split(",")

                    if len(tags) > 0:
                        if len(ti_copy.tags) > 0:
                            raise AnsibleParserError(
                                "Include tasks should not specify tags in more than one way (both via args and directly on the task). "
                                "Mixing styles in which tags are specified is prohibited for whole import hierarchy, not only for single import statement",
                                obj=task_ds,
                                suppress_extended_error=True,
                            )
                        display.deprecated(
                            "You should not specify tags in the include parameters. All tags should be specified using the task-level option"
                        )
                    else:
                        tags = ti_copy.tags[:]

                    # now we extend the tags on each of the included blocks
                    for b in included_blocks:
                        b.tags = list(set(b.tags).union(tags))
                    # END FIXME

                    # FIXME: handlers shouldn't need this special handling, but do
                    #        right now because they don't iterate blocks correctly
                    if use_handlers:
                        for b in included_blocks:
                            task_list.extend(b.block)
                    else:
                        task_list.extend(included_blocks)
                else:
                    task_list.append(t)

            elif "include_role" in task_ds:
                ir = IncludeRole.load(
                    task_ds,
                    block=block,
                    role=role,
                    task_include=None,
                    variable_manager=variable_manager,
                    loader=loader,
                )

                #   1. the user has set the 'static' option to false or true
                #   2. one of the appropriate config options was set
                if ir.static is not None:
                    is_static = ir.static
                else:
                    display.debug("Determine if include_role is static")
                    # Check to see if this include is dynamic or static:
                    all_vars = variable_manager.get_vars(
                        loader=loader, play=play, task=ir
                    )
                    templar = Templar(loader=loader, variables=all_vars)
                    needs_templating = False
                    for param in ir.args:
                        if templar._contains_vars(ir.args[param]):
                            if not templar.is_template(ir.args[param]):
                                needs_templating = True
                                break
                    is_static = (
                        C.DEFAULT_TASK_INCLUDES_STATIC
                        or (use_handlers and C.DEFAULT_HANDLER_INCLUDES_STATIC)
                        or (
                            not needs_templating
                            and ir.all_parents_static()
                            and not ir.loop
                        )
                    )
                    display.debug(
                        "Determined that if include_role static is %s" % str(is_static)
                    )

                if is_static:
                    # uses compiled list from object
                    blocks, _ = ir.get_block_list(
                        variable_manager=variable_manager, loader=loader
                    )
                    t = task_list.extend(blocks)
                else:
                    # passes task object itself for latter generation of list
                    t = task_list.append(ir)
            else:
                if use_handlers:
                    t = Handler.load(
                        task_ds,
                        block=block,
                        role=role,
                        task_include=task_include,
                        variable_manager=variable_manager,
                        loader=loader,
                    )
                else:
                    t = Task.load(
                        task_ds,
                        block=block,
                        role=role,
                        task_include=task_include,
                        variable_manager=variable_manager,
                        loader=loader,
                    )

                task_list.append(t)

    return task_list