LaTex rendering fails

[af-rotundo]

Information

• Qiskit Terra version: 0.17.1
• Python version: 3.8.5
• Operating system: macOS 11.4

What is the current behavior?

I'm trying to draw the following simple circuit with LaTex

However, the output is empty when I pass the option output='latex'.

The problem is only present with the Initialize gate. Also, the problem is not present for different numbers of quantum/classical registers, e.g. the circuit is drawn correctly if one quantum register is removed.

Steps to reproduce the problem

Run the following code in JupyterLab

from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister
from qiskit.quantum_info import random_statevector
from qiskit.extensions import Initialize

qr = QuantumRegister(5, name="q")
cr1, cr2 = ClassicalRegister(1, name="cr1"), ClassicalRegister(1, name="cr2")
scr = QuantumCircuit(qr,cr1,cr2)
psi = random_statevector(2)
init_gate = Initialize(psi)
scr.append(init_gate, [0])
scr.draw(output='latex')

What is the expected behavior?

For example if we remove one quantum register, the circuit is rendered correctly. Try

from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister
from qiskit.quantum_info import random_statevector
from qiskit.extensions import Initialize

qr = QuantumRegister(4, name="q")
cr1, cr2 = ClassicalRegister(1, name="cr1"), ClassicalRegister(1, name="cr2")
scr = QuantumCircuit(qr,cr1,cr2)
psi = random_statevector(2)
init_gate = Initialize(psi)
scr.append(init_gate, [0])
scr.draw(output='latex')

Suggested solutions

[epelaaez]

Using the following Qiskit version (the one from the IBM Quantum Lab):

{'qiskit-terra': '0.18.1', 'qiskit-aer': '0.8.2', 'qiskit-ignis': '0.6.0', 'qiskit-ibmq-provider': '0.16.0', 'qiskit-aqua': '0.9.4', 'qiskit': '0.29.0', 'qiskit-nature': '0.1.5', 'qiskit-finance': '0.2.0', 'qiskit-optimization': '0.2.1', 'qiskit-machine-learning': '0.2.0'}

I'm able to get the drawing you're having trouble with:

It probably has something to do with you using 0.17.1.

[af-rotundo]

The problem was indeed the outdated package, thanks.