ValueError: Field 'id' expected a number but got a string

[codingjoe]

The following error occurs if someone tries to access a URL workflow detail view with a non integer primary key in the URL.
We should adjust the URL pattern to only accept integers to avoid this error and raise the expected 404 response.

ValueError: invalid literal for int() with base 10: 'some-string'
  File "django/db/models/fields/__init__.py", line 1774, in get_prep_value
    return int(value)
ValueError: Field 'id' expected a number but got 'some-string'.
  File "django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "django/core/handlers/base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "newrelic/hooks/framework_django.py", line 554, in wrapper
    return wrapped(*args, **kwargs)
  File "django/views/generic/base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "newrelic/hooks/framework_django.py", line 944, in wrapper
    return wrapped(*args, **kwargs)
  File "django/views/generic/base.py", line 98, in dispatch
    return handler(request, *args, **kwargs)
  File "django/views/generic/detail.py", line 106, in get
    self.object = self.get_object()
  File "django/views/generic/detail.py", line 36, in get_object
    queryset = queryset.filter(pk=pk)
  File "django/db/models/query.py", line 942, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File "django/db/models/query.py", line 962, in _filter_or_exclude
    clone._filter_or_exclude_inplace(negate, *args, **kwargs)
  File "django/db/models/query.py", line 969, in _filter_or_exclude_inplace
    self._query.add_q(Q(*args, **kwargs))
  File "django/db/models/sql/query.py", line 1358, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "django/db/models/sql/query.py", line 1377, in _add_q
    child_clause, needed_inner = self.build_filter(
  File "django/db/models/sql/query.py", line 1319, in build_filter
    condition = self.build_lookup(lookups, col, value)
  File "django/db/models/sql/query.py", line 1165, in build_lookup
    lookup = lookup_class(lhs, rhs)
  File "django/db/models/lookups.py", line 24, in __init__
    self.rhs = self.get_prep_lookup()
  File "django/db/models/fields/related_lookups.py", line 117, in get_prep_lookup
    self.rhs = target_field.get_prep_value(self.rhs)
  File "django/db/models/fields/__init__.py", line 1776, in get_prep_value
    raise e.__class__(