A new take on debuggers for quantum transpilers. This repository presents a debugger for the qiskit transpiler in the form of a light weight jupyter widget. Built as a project for the Qiskit Advocate Mentorship Program, Fall 2021.

1. To install the debugger using pip (a python package manager), use -

pip install -i https://test.pypi.org/simple/ --extra-index https://pypi.org/simple/ qiskit-trebugger

• PIP will handle the dependencies required for the package automatically and would install the latest version.
• Currently the project is hosted as a test package and would be hosted on the real index when tests are added.

2. To directly install via github follow the steps below after using git clone:

git clone https://github.com/TheGupta2012/qiskit-timeline-debugger.git

• Make sure python3 and pip are installed in your system
• Use pip install -r requirements to install the debugger dependencies
• Note : with this method, you can only use the debugger in the installed directory

• After installing the package, import the Debugger instance from qiskit_trebugger package.
• To run the debugger, simply replace the call to transpile() method of the qiskit module with debug() method of your debugger instance. For an example -

from qiskit import QuantumCircuit
from qiskit.test.mock import FakeCasablanca
from qiskit_trebugger import Debugger

debugger = Debugger()
backend = FakeCasablanca()
circuit = QuantumCircuit(3)
circuit.h(0)
circuit.cx(0,1)
circuit.cx(1,2)
circuit.measure_all()
# replace transpile call 
debugger.debug(circuit, backend = backend)

• On calling the debug method, a new jupyter widget is displayed providing a complete summary and details of the transpilation process for circuits of < 2000 depth
• With an easy to use and responsive interface, users can quickly see which transpiler passes ran when, how they changed the quantum circuit and what exactly changed.

• See your circuit changing while going through the transpilation process for a target quantum processor.
• A new custom feature enabling visual diffs for quantum circuits, allows you to see what exactly changed in your circuit using the matplotlib drawer of the qiskit module.

Example

• Circuit 1

• Circuit 2

• Allows users to quickly scan through how the major properties of a circuit transform during each transpilation pass.
• Helps to quickly isolate the passes which were responsible for the major changes in the resultant circuit.

• Easily parse actions of the transpiler with logs emitted by each of its constituent passes and changes to the property set during transpilation
• Every log record is color coded according to the level of severity i.e. DEBUG, INFO, WARNING and CRITICAL.

• Please follow [this](to be added) link for a demonstration of our project.

• Aboulkhair Foda
• Harshit Gupta