Issues

• pecos-neo with_noiseless_gate has no effect on composite channels, preparation or measurement

  bugrustseverity:critical
  PECOS-packages/PECOS#1575 · Filter by author ciaranra opened on Nov 1, 2026

• pecos-neo builders treat gates on leaked qubits differently, and two of them differ from the engines

  bugrustseverity:critical
  PECOS-packages/PECOS#1574 · Filter by author ciaranra opened on Nov 1, 2026

• pecos-neo crosstalk does not collapse the affected qubit or use its state, unlike the engines

  bugrustseverity:critical
  PECOS-packages/PECOS#1573 · Filter by author ciaranra opened on Nov 1, 2026

• AST Guppy emitter renders classical expressions Guppy rejects

  bugpythonseverity:medium
  PECOS-packages/PECOS#1569 · Filter by author ciaranra opened on Nov 1, 2026

• pecos-neo channel_action runs a wrapped channel once per operand, doubling two-qubit rates

  bugrustseverity:critical
  PECOS-packages/PECOS#1568 · Filter by author ciaranra opened on Nov 1, 2026

• Rust Selene compiler pin is stuck at tket2 96865e91 by Windows path lengths

  enhancementrust
  PECOS-packages/PECOS#1541 · Filter by author ciaranra opened on Oct 31, 2026

• TimingRunner.total_time is never accumulated, so threshold and speed helpers report zero time

  bugpythonseverity:medium
  PECOS-packages/PECOS#1537 · Filter by author ciaranra opened on Oct 30, 2026

• CoinToss.run_circuit rejects removed_locations, so CoinToss fails under the Standard runner

  bugpythonseverity:high
  PECOS-packages/PECOS#1536 · Filter by author ciaranra opened on Oct 30, 2026

• Legacy HybridEngine never clears leaked qubits on unleak (string compared with a set)

  bugpythonseverity:low
  PECOS-packages/PECOS#1535 · Filter by author ciaranra opened on Oct 30, 2026

• pecos.simulators wrappers: remaining known-wrong behaviours pinned by the characterization corpus

  bugpythonseverity:medium
  PECOS-packages/PECOS#1515 · Filter by author ciaranra opened on Oct 28, 2026

• Support loop-variable qubit indices in SLR For loops

  enhancementpython
  PECOS-packages/PECOS#1512 · Filter by author ciaranra opened on Oct 28, 2026

• ErrorSet rejects the gate-symbol strings its API advertises (regression from #204)

  bugpythonseverity:high
  PECOS-packages/PECOS#1500 · Filter by author ciaranra opened on Oct 26, 2026

• from_quantum_circuit ignores qvars and puts every qubit in one q register

  enhancementpython
  PECOS-packages/PECOS#1498 · Filter by author ciaranra opened on Oct 26, 2026

• Some seed derivations give identical streams for constructed seed pairs

  bugrustseverity:low
  PECOS-packages/PECOS#1495 · Filter by author ciaranra opened on Oct 26, 2026

• pecos.simulators wrappers apply part of a gate batch before rejecting a bad location

  bugpythonseverity:medium
  PECOS-packages/PECOS#1480 · Filter by author ciaranra opened on Oct 25, 2026

• pz/px/py (and mpz etc.) leave the qubit in the wrong state when a batch repeats a qubit

  bugrustseverity:critical
  PECOS-packages/PECOS#1479 · Filter by author ciaranra opened on Oct 25, 2026

• DenseStab gates reach unchecked indexing with out-of-range qubit indices (UB in release)

  bugrustseverity:critical
  PECOS-packages/PECOS#1471 · Filter by author ciaranra opened on Oct 25, 2026

• CppSparseStab::mz always reports is_deterministic = false

  bugrustseverity:critical
  PECOS-packages/PECOS#1470 · Filter by author ciaranra opened on Oct 25, 2026

• SparseStab: sqrt(n) work per gate on surface and color codes at millions of qubits

  enhancementrust
  PECOS-packages/PECOS#1469 · Filter by author ciaranra opened on Oct 25, 2026

• Frontier v2 prepared decoder keeps an unused trellis scratch for the whole decode call

  enhancementrust
  PECOS-packages/PECOS#1453 · Filter by author ciaranra opened on Oct 23, 2026

• SZZ physical-prefix lowering cannot lower the pending Cliffords that X-basis axis-cycle frames need

  bugpythonseverity:high
  PECOS-packages/PECOS#1450 · Filter by author ciaranra opened on Oct 23, 2026

• SZZ round-order check plans give random noiseless detectors unless ancilla_budget is 1 or 2

  bugpythonseverity:critical
  PECOS-packages/PECOS#1449 · Filter by author ciaranra opened on Oct 23, 2026

• Investigate Frontier ordering sensitivity on surface-code DEMs

  PECOS-packages/PECOS#1447 · Filter by author qciaran opened on Oct 23, 2026

• NoiseConfig::set_idle_rz drops large angles and uses the wrong duration law

  bugrustseverity:critical
  PECOS-packages/PECOS#1445 · Filter by author ciaranra opened on Oct 23, 2026
  1

• Stim-backed surface DEM helpers silently drop NoiseParameters fields

  bugpythonseverity:critical
  PECOS-packages/PECOS#1444 · Filter by author ciaranra opened on Oct 23, 2026