from jinja2 import DictLoader, Environment

loader = DictLoader({
    'test': """
        {% import 'macro' as macros %}
        {{ macros.testing() }}""",
    'macro': """
        {% macro testing() %}
            macro reference to global: {{foo}}
            {% include 'nested' %}
        {% endmacro %}""",
    'nested': 'nested reference to global: {{foo}}'
})
env = Environment(loader=loader, cache_size=0)

# When the template is provided globals and includes a macro
# the global variable is not available to the macro.
template = env.get_template('test', globals={'foo': 'bar'})
# This fails and doesn't show the global foo value:
# macro reference to global:
# nested reference to global:
print template.render()

# If you set the global value after getting the template then the macro
# is able to reference the global variable.
template = env.get_template('test')
template.globals['foo'] = 'bar'
# This works, but I think it is a hack or isn't recommended.
# macro reference to global: bar
# nested reference to global: bar
print template.render()