Invalid circuit produced during TASO optimisation

[aborgna-q]

The following script panics mid-optimisation. It seems an invalid circuit gets produced somewhere during the TASO run.

from pytket.qasm.qasm import circuit_from_qasm
from pytket.passes import PauliSquash
from pyrs.pyrs import optimiser

def compile(circ):
    print(f"Compiling optimiser")
    opt = optimiser.TasoOptimiser.load_precompiled("nam_6_3.rwr")

    PauliSquash().apply(circ)
    return opt.optimise(circ, 30, log_progress="/tmp/progress.log")

if __name__ == "__main__":
    circ = circuit_from_qasm("failing.qasm")
    compile(circ)

Failing circ:

failing.qasm.tar.gz

[aborgna-q]

Update:
This circuit fails to validate after the first rewrite without the PauliSquash step.

OPENQASM 2.0;
include "qelib1.inc";

qreg q[3];
cx q[2],q[0];
cx q[1],q[0];
u3(0.5*pi,0.0*pi,0.5*pi) q[2];

Error:

Edge mismatch: Extensions at source node Node(11) ([IdentList("prelude")]) exceed those at target Node(12) ([])

original-circuit

post-rewrite circuit

[aborgna-q]

Reproducible test case in here: https://github.com/CQCL/tket2/blob/debug/validation-fail-example/examples/failing_validation.rs

Checkout the debug/validation-fail-example branch and run
cargo run --example failing_validation

[croyzor]

The test case seems to be working now after recent changes to extension inference! I rebased on the current head of tket2 (d8a7bd5) and running the example gives no such error! I've pushed the rebase to the debug/validation-fail-example branch

[aborgna-q]

Seems to be fixed 👍
(It'd be nice to know how :P )