# pyomo 4.4.1
# python 3.5
from pyomo.environ import *
import numpy

m = ConcreteModel()

m.T = RangeSet(10)
m.v = Var(initialize=1, bounds=(0,None))
m.c = Var(m.T, initialize=20)

def rule(m, t):
    h = numpy.float32(1.0)
    # This works
    return m.c[t]  == h * m.c[t]
m.X = Constraint(m.T, rule=rule)

def rule(m, t):
    h = numpy.float32(1.0)
    # This works
    return m.c[t]  == h * m.c[t] * m.v
m.X = Constraint(m.T, rule=rule)

def rule(m, t):
    h = numpy.float32(1.0)
    # This fails
    return m.c[t]  == h * m.v
m.x = Constraint(m.T, rule=rule)

ERROR: Rule failed when generating expression for constraint x with index 1:
    KeyError: "Error accessing indexed component: Cannot treat the scalar component 'v' as an array"
ERROR: Constructing component 'x' from data=None failed:
    KeyError: "Error accessing indexed component: Cannot treat the scalar component 'v' as an array"
Traceback (most recent call last):
  File "tmp.py", line 26, in <module>
    m.x = Constraint(m.T, rule=rule)
  File "/Users/wehart/home/src/python35/src/pyomo/pyomo/core/base/block.py", line 483, in __setattr__
    self.add_component(name, val)
  File "/Users/wehart/home/src/python35/src/pyomo/pyomo/core/base/block.py", line 849, in add_component
    val.construct(data)
  File "/Users/wehart/home/src/python35/src/pyomo/pyomo/core/base/constraint.py", line 736, in construct
    ndx)
  File "/Users/wehart/home/src/python35/src/pyomo/pyomo/core/base/misc.py", line 59, in apply_indexed_rule
    return rule(model, index)
  File "tmp.py", line 25, in rule
    return m.c[t]  == h * m.v
  File "/Users/wehart/home/src/python35/src/pyomo/pyomo/core/base/indexed_component.py", line 499, in __getitem__
    raise KeyError(msg)
KeyError: "Error accessing indexed component: Cannot treat the scalar component 'v' as an array"