WalshDiagonalSynthesisPass defaults to RuntimeError

[mariagg-quantinuum]

When I try to run a circuit through WalshDiagonalSynthesisPass I always end up with a RuntimeError:

---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
File ~/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/compiler/compiler.py:440, in Compiler._send_recv(self, msg, payload)
    438     self.conn.send((msg, payload))
--> [440](.../tests/~/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/compiler/compiler.py:440)     return self._recv_handle_log_error()
    442 except Exception as e:

File ~/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/compiler/compiler.py:468, in Compiler._recv_handle_log_error(self)
    467 elif msg == RuntimeMessage.ERROR:
--> [468](.../tests/~/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/compiler/compiler.py:468)     raise RuntimeError(payload)
    470 else:
    471     # Communication between runtime server and compiler
    472     # is always round-trip. Once we have received our
   (...)
    477     # process every arrived message before returning.
    478     # Hence, the `or self.conn.poll()` in the while condition.

RuntimeError: Traceback (most recent call last):
  File "/Users/maria.gragera-garces/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/runtime/worker.py", line 459, in _try_step_next_ready_task
    future = task.step(self._get_desired_result(task))
  File "/Users/maria.gragera-garces/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/runtime/task.py", line 115, in step
    to_return = self.coro.send(send_val)
  File "/Users/maria.gragera-garces/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/runtime/task.py", line 149, in run
    return await self.fnargs[0](*self.fnargs[1], **self.fnargs[2])
  File "/Users/maria.gragera-garces/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/compiler/task.py", line 54, in run
...
    443 self.conn = None
    444 self.close()
--> [445](.../tests/~/Documents/tket2/.venv/lib/python3.10/site-packages/bqskit/compiler/compiler.py:445) raise RuntimeError('Server connection unexpectedly closed.') from e

RuntimeError: Server connection unexpectedly closed.

Here is an example of what I am trying to run:

from pytket import Circuit
from bqskit.ext import pytket_to_bqskit, bqskit_to_pytket
from bqskit.compiler import Compiler
from bqskit.passes import WalshDiagonalSynthesisPass
from tket.circuit import Tk2Circuit

c = Circuit(3).CX(0,1).CX(1,0).CX(0,1).CX(1,0).CX(0,1).CX(1,0).CX(0,2)
bqc = pytket_to_bqskit(c)

with Compiler(num_workers=1) as comp:
    out_bqc = comp.compile(bqc, [WalshDiagonalSynthesisPass()])

[edyounis]

The full error message includes:

  File "/home/edyounis/.local/share/Workspace/bqskit/.env/lib/python3.13/site-packages/bqskit/utils/math.py", line 191, in pauliz_expansion
    raise ValueError(msg)
ValueError: H must be a diagonal matrix.


The above exception was the direct cause of the following exception:

The WalshDiagonalSynthesisPass is only designed to handle Diagonal matrices, which your input is not. This is documented in the name and the pass documentation.

[edyounis]

No worries, we should probably get a more descriptive and earlier error message going for this. Would you mind actually making a quick issue requesting better error messages for this situation?

[mariagg-quantinuum]

will do :)

[mariagg-quantinuum]

#353

[edyounis]

Thanks! Looking at this again, it looks like you encountered a different error, which presents as a bug, rather than a documentation mishap. My bad for assuming. Do you mind sharing your OS?

[mariagg-quantinuum]

right, that would be macOS Sequoia v15.7.2