RuntimeError: OrderedDict mutated during iteration

When trying to run all diagnostics (using 0.9-rc2 raspberry2 image), I got this error:

[2016-07-09 16:05:31,603] django.request ERROR    Internal Server Error: /plinth/sys/diagnostics/
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/django/core/handlers/base.py", line 174, in get_response
    response = self.process_exception_by_middleware(e, request)
  File "/usr/lib/python3/dist-packages/django/core/handlers/base.py", line 172, in get_response
    response = response.render()
  File "/usr/lib/python3/dist-packages/django/template/response.py", line 160, in render
    self.content = self.rendered_content
  File "/usr/lib/python3/dist-packages/django/template/response.py", line 137, in rendered_content
    content = template.render(context, self._request)
  File "/usr/lib/python3/dist-packages/django/template/backends/django.py", line 95, in render
    return self.template.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 206, in render
    return self._render(context)
  File "/usr/lib/python3.5/contextlib.py", line 77, in __exit__
    self.gen.throw(type, value, traceback)
  File "/usr/lib/python3/dist-packages/django/template/context.py", line 264, in bind_template
    yield
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 206, in render
    return self._render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 197, in _render
    return self.nodelist.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 992, in render
    bit = node.render_annotated(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 959, in render_annotated
    return self.render(context)
  File "/usr/lib/python3/dist-packages/django/template/loader_tags.py", line 173, in render
    return compiled_parent._render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 197, in _render
    return self.nodelist.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 992, in render
    bit = node.render_annotated(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 959, in render_annotated
    return self.render(context)
  File "/usr/lib/python3/dist-packages/django/template/loader_tags.py", line 173, in render
    return compiled_parent._render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 197, in _render
    return self.nodelist.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 992, in render
    bit = node.render_annotated(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 959, in render_annotated
    return self.render(context)
  File "/usr/lib/python3/dist-packages/django/template/loader_tags.py", line 69, in render
    result = block.nodelist.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 992, in render
    bit = node.render_annotated(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 959, in render_annotated
    return self.render(context)
  File "/usr/lib/python3/dist-packages/django/template/loader_tags.py", line 69, in render
    result = block.nodelist.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 992, in render
    bit = node.render_annotated(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 959, in render_annotated
    return self.render(context)
  File "/usr/lib/python3/dist-packages/django/template/loader_tags.py", line 69, in render
    result = block.nodelist.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 992, in render
    bit = node.render_annotated(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 959, in render_annotated
    return self.render(context)
  File "/usr/lib/python3/dist-packages/django/template/defaulttags.py", line 326, in render
    return nodelist.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 992, in render
    bit = node.render_annotated(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 959, in render_annotated
    return self.render(context)
  File "/usr/lib/python3/dist-packages/django/template/defaulttags.py", line 326, in render
    return nodelist.render(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 992, in render
    bit = node.render_annotated(context)
  File "/usr/lib/python3/dist-packages/django/template/base.py", line 959, in render_annotated
    return self.render(context)
  File "/usr/lib/python3/dist-packages/django/template/defaulttags.py", line 179, in render
    for i, item in enumerate(values):
RuntimeError: OrderedDict mutated during iteration