ImportError: cannot import name '_TEMP_BIT_NAME' from 'pytket._tket.circuit'

[fuglede]

When installing pytket in a fresh environment, using Python 3.11/Pip from Conda, then Pip to resolve all dependencies, I get the below error when importing anything the Qiskit-TKET converters. Versions are:

pip                       23.2.1          py311h06a4308_0  
python                    3.11.5               h955ad1f_0  
pytket                    1.19.1                   pypi_0    pypi
pytket-qiskit             0.39.0                   pypi_0    pypi
qiskit                    0.42.1                   pypi_0    pypi
qiskit-aer                0.12.0                   pypi_0    pypi
qiskit-dynamics           0.4.2                    pypi_0    pypi
qiskit-experiments        0.5.3                    pypi_0    pypi
qiskit-finance            0.3.4                    pypi_0    pypi
qiskit-ibm-experiment     0.3.5                    pypi_0    pypi
qiskit-ibm-runtime        0.9.3                    pypi_0    pypi
qiskit-ibmq-provider      0.20.2                   pypi_0    pypi
qiskit-machine-learning   0.6.1                    pypi_0    pypi
qiskit-nature             0.6.0                    pypi_0    pypi
qiskit-optimization       0.5.0                    pypi_0    pypi
qiskit-terra              0.23.3                   pypi_0    pypi

The full traceback is below:

---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
Cell In[1], line 4
      2 import matplotlib.pyplot as plt
      3 from pytket.passes import RemoveRedundancies, CliffordSimp
----> 4 from pytket.extensions.qiskit import qiskit_to_tk, tk_to_qiskit

File ~/miniconda3/envs/synthesis/lib/python3.11/site-packages/pytket/extensions/qiskit/__init__.py:18
     16 # _metadata.py is copied to the folder after installation.
     17 from ._metadata import __extension_version__, __extension_name__  # type: ignore
---> 18 from .backends import (
     19     IBMQBackend,
     20     NoIBMQAccountError,
     21     AerBackend,
     22     AerStateBackend,
     23     AerUnitaryBackend,
     24     IBMQEmulatorBackend,
     25 )
     26 from .backends.config import set_ibmq_config
     27 from .qiskit_convert import qiskit_to_tk, tk_to_qiskit, process_characterisation

File ~/miniconda3/envs/synthesis/lib/python3.11/site-packages/pytket/extensions/qiskit/backends/__init__.py:16
      1 # Copyright 2019-2023 Cambridge Quantum Computing
      2 #
      3 # Licensed under the Apache License, Version 2.0 (the "License");
   (...)
     12 # See the License for the specific language governing permissions and
     13 # limitations under the License.
     14 """Backends for connecting to IBM devices and simulators directly from pytket"""
---> 16 from .ibm import IBMQBackend, NoIBMQAccountError
     17 from .aer import AerBackend, AerStateBackend, AerUnitaryBackend
     18 from .ibmq_emulator import IBMQEmulatorBackend

File ~/miniconda3/envs/synthesis/lib/python3.11/site-packages/pytket/extensions/qiskit/backends/ibm.py:57
     55 from pytket.backends.backendresult import BackendResult
     56 from pytket.backends.resulthandle import _ResultIdTuple
---> 57 from pytket.extensions.qiskit.qiskit_convert import (
     58     process_characterisation,
     59     get_avg_characterisation,
     60 )
     61 from pytket.extensions.qiskit._metadata import __extension_version__
     62 from pytket.passes import (  # type: ignore
     63     BasePass,
     64     auto_rebase_pass,
   (...)
     74     NaivePlacementPass,
     75 )

File ~/miniconda3/envs/synthesis/lib/python3.11/site-packages/pytket/extensions/qiskit/qiskit_convert.py:72
     58 from qiskit.extensions.unitary import UnitaryGate  # type: ignore
     59 from pytket.circuit import (  # type: ignore
     60     CircBox,
     61     Circuit,
   (...)
     70     QControlBox,
     71 )
---> 72 from pytket._tket.circuit import _TEMP_BIT_NAME  # type: ignore
     73 from pytket.pauli import Pauli, QubitPauliString  # type: ignore
     74 from pytket.architecture import Architecture, FullyConnected  # type: ignore

ImportError: cannot import name '_TEMP_BIT_NAME' from 'pytket._tket.circuit' (/home/user/miniconda3/envs/synthesis/lib/python3.11/site-packages/pytket/_tket/circuit.cpython-311-x86_64-linux-gnu.so)

[fuglede]

As a workaround, I can remove the broken import on qiskit_convert.py:72, and change qiskit_convert.py:637 from

        if b.reg_name != _TEMP_BIT_NAME and (

to

        if b.reg_name != 60 and (

and get something that seems to work (without knowing what _TEMP_BIT_NAME was supposed to be).

[cqc-alec]

Yes, the latest update to pytket (1.19) requires that pytket-qiskit also be updated. Please could you update to the latest pytket-qiskit and try again? Thanks!

[cqc-alec]

Closing this: please reopen if still an issue after updating pytket.

[fuglede]

The versions above were obtained by installing the packages in a blank environment (alongside a handful of other packages), so Pip's solver found the versions to be compatible; maybe some constraints are missing in the dependency specification of pytket then?

Moreover, if I run pip install --upgrade pytket-qiskit, it mages to go from 0.39.0 to 0.44.0, but the exact same error occurs.

[fuglede]

Looks like I can't reopen the issue.

[cqc-alec]

You probably have to pip install --upgrade pytket as well.

This was in fact a bug, in that we updated pytket without realizing that doing so would break pytket-qiskit: we normally try to keep backwards compatibility in pytket 1.x releases, but forgot that some of the extensions import underscored symbols which aren't covered by that guarantee.

[fuglede]

That takes me from pytket-1.19.1 to pytket-1.20.1; the error persists.

[fuglede]

Edit; sorry, what's failing is a manual run of

from pytket._tket.circuit import _TEMP_BIT_NAME

but I noticed qiskit_convert.py effectively branches on version numbers now, avoiding this import, so this isn't an issue in practice.

[cqc-alec]

OK, sorry for the inconvenience this has caused.

[fuglede]

No worries, thanks for your work on TKET!

[tanmay0550]

I used the above suggestion, but it's still showing the same issue

cannot import name '_TEMP_BIT_NAME' from 'pytket._tket.circuit

[cqc-alec]

I used the above suggestion, but it's still showing the same issue

cannot import name '_TEMP_BIT_NAME' from 'pytket._tket.circuit

Is this using pytket-qiskit? Which version?