DIMACS output bug

[CoolA1d]

Getting a weird error with the following script:

from z3 import *

a = BitVec('a', 32)
b = BitVec('b', 32)

equation1 = a + b == 0xdeadbeef % 2 ** 32
equation2 = b == 2 * a

g = Goal()
g.add(equation1, equation2)

t = Then('simplify', 'bit-blast', 'tseitin-cnf')

r = t(g)
print(r[0].dimacs())

It's saying "b'Goal is not converted into CNF. Preprocess by optional bit-blasting and applying tseitin-cnf'". However as you can see in the code I apply the tactic right before I query dimacs. Is there an error in my code somewhere?