from qiskit import QuantumCircuit

# GhostCompose inside a loop: compose() is called repeatedly across
# iterations, each discarding its return value. Engine A only.
qc = QuantumCircuit(1, 1)
for i in range(5):
    sub = QuantumCircuit(1, 1)
    sub.h(0)
    qc.compose(sub)    # BUG (x5 iters): compose() return value discarded