Issues

• Switch from mypy to Pyrefly for Python type checking

  Feature request

  quantumlib/qsim#1091 · Filter by author mhucka opened on Jul 6, 2026
  1

• Binary wheels for Python 3.14

  a: devopsP1
  Task

  quantumlib/qsim#1017 · Filter by author pavoljuhas opened on Feb 26, 2026
  

• Investigate the use of uv for dependency management

  a: circuitsno QC knowledge neededP2
  Feature request

  quantumlib/qsim#977 · Filter by author mhucka opened on Dec 31, 2025
  1

• Run code through clang-format to normalize formatting

  a: c++a: health
  Task

  quantumlib/qsim#927 · Filter by author mhucka opened on Nov 3, 2025
  1

  

• Switch to ruff as the formatter

  a: devopsa: pythoncontributors welcomeno QC knowledge needed
  Task

  quantumlib/qsim#916 · Filter by author mhucka opened on Oct 28, 2025
  3

  

• Provide a way to avoid copying state vector from Cirq

  a: performancea: pythona: qsimcirqcontributors welcomeno QC knowledge neededP2
  Feature request

  quantumlib/qsim#893 · Filter by author mhucka opened on Sep 23, 2025
  13

• Documentation needs to be reviewed and updated

  a: docscontributors welcomeP1
  Task

  quantumlib/qsim#891 · Filter by author mhucka opened on Sep 22, 2025 · Release 0.23.0
  1

• qsimcirq can handle large circuit?

  P1s: awaiting-response
  Question

  quantumlib/qsim#869 · Filter by author CoolMLAI opened on Aug 20, 2025 · Release 0.23.0
  8

  

• Provide a way to get a pointer to the GPU memory for the final state vector

  a: gpu
  Feature request

  quantumlib/qsim#836 · Filter by author mhucka opened on Jul 20, 2025
  2

  

• Bazel builds should be hermetic, but they're not

  a: devopsa: healthcontributors welcome
  Bug report

  quantumlib/qsim#802 · Filter by author mhucka opened on Jun 22, 2025 · Release 0.24.0
  3

• Investigate why some Python expectation value tests failed with NumPy 2

  a: devopsa: healthcontributors welcomegood first issueP1
  Bug report

  quantumlib/qsim#754 · Filter by author mhucka opened on Jun 10, 2025 · Release 0.23.0
  4

  

• denormals_are_zeros setting has unexpected side effects

  a: healthcontributors welcomeP2
  Bug report

  quantumlib/qsim#666 · Filter by author richrines1 opened on Jul 22, 2024 · Release 0.24.0
  2

• Question about multi-GPU support

  a: gpuP1
  Question

  quantumlib/qsim#635 · Filter by author jakurzak opened on Nov 7, 2023 · Release 0.23.0
  3

  

• Avoid statevector copy in qsim.simulate(qc, initial_state=sv)

  a: c++a: performancea: pythoncontributors welcomeno QC knowledge needed
  Feature request

  quantumlib/qsim#617 · Filter by author hthayko opened on Jun 24, 2023 · Release 0.24.0
  12

• qsim 0.16 requires more RAM for a simple Hadamards circuit compared to qsim 0.12

  a: performanceP2
  Bug report

  quantumlib/qsim#612 · Filter by author rht opened on May 19, 2023 · Release 0.24.0
  14

• Dynamically link to CUDA and cuQuantum

  a: devopsa: gpucontributors welcome
  Feature request

  quantumlib/qsim#601 · Filter by author 95-martin-orion opened on Apr 5, 2023 · Release 0.23.0
  4

  

• cirq.ClassicallyControlledOperation raises "ValueError: Encountered unparseable op"

  a: qsimcirqcontributors welcomeP1
  Bug report

  quantumlib/qsim#571 · Filter by author rht opened on Dec 16, 2022 · Release 0.23.0
  1

• cuStateVec issue on GPU in Google Colab

  a: gpuP1
  Bug report

  quantumlib/qsim#542 · Filter by author 95-martin-orion opened on Jul 11, 2022 · Release 0.23.0
  3

  

• cirq.Circuit(cirq.I(cirq.LineQubit(0))) segfaults when trying to execute on qsim

  a: healtha: qsimcirqP1
  Bug report

  quantumlib/qsim#540 · Filter by author vtomole opened on Jul 8, 2022 · Release 0.23.0
  2

• Support CircuitOperation(use_repetition_ids=False)

  Feature request

  quantumlib/qsim#533 · Filter by author 95-martin-orion opened on Jun 6, 2022
  4

• Swap endianness of MPS simulator to match that of the state vector simulator

  a: mps
  Feature request

  quantumlib/qsim#492 · Filter by author MichaelBroughton opened on Jan 4, 2022

• Not building with cuQuantum SDK (and cirq)

  a: gpuP1
  Bug report

  quantumlib/qsim#481 · Filter by author rugantio opened on Nov 19, 2021 · Release 0.23.0
  6

  

• Improve multinode tutorial

  a: docs
  Feature request

  quantumlib/qsim#450 · Filter by author 95-martin-orion opened on Oct 11, 2021 · Release 0.24.0
  1

• Support MPS in trajectory simulation

  a: mpscontributors welcome
  Feature request

  quantumlib/qsim#440 · Filter by author MichaelBroughton opened on Sep 30, 2021

• Support MPS in pybindings

  a: mpsa: pythona: qsimcirqcontributors welcomegood first issue
  Feature request

  quantumlib/qsim#439 · Filter by author MichaelBroughton opened on Sep 30, 2021
  2