py-0.9.0.dev0

PECOS 0.9.0.dev0 (pre-release)

Highlight: Rust classical interpreter is now the default

HybridEngine's default classical interpreter is now the Rust-backed RustPhirClassicalInterpreter (previously the pure-Python PhirClassicalInterpreter). For valid PHIR programs supplied as a dict, JSON string, or to_phir_dict()-convertible object it is behaviorally equivalent — differentially validated against the Python interpreter (~3,200 fuzzed programs, QASM-generated-PHIR differentials, exact exception-type parity).

Escape hatch: to restore the previous behavior, construct the engine with HybridEngine(cinterp="python").

Boundary behavior was brought to parity so the switch is not silent: phir_validate now schema-validates on the Rust path; division by zero raises ZeroDivisionError and undefined classical variables raise KeyError on both interpreters; undeclared assignment/ffcall/measurement targets fail fast (matching Python) instead of being auto-created; check_ffc fails fast on missing foreign functions; run_multisim works with to_dict-capable foreign objects. Known limitation: PyPHIR program objects are not accepted by the Rust interpreter (clear TypeError; use a dict/JSON or cinterp="python").

Also in this release

• PHIR engine fail-fast fixes (#345): invalid variable definitions and out-of-range measurement writes error instead of being silently swallowed; the no-return measurement index is absolute across batches.
• ~41 previously-dormant pecos-phir-json integration tests revived and running in CI.
• Signed PHIR registers render as two's-complement binary strings (i(S+1) semantics); WASM fixtures corrected to i32 size 31.
• Supply-chain: cxx 1.0.195, Go 1.26.5, triaged cgmath advisories (#349).
• pecos-rslib-llvm is published alongside pecos-rslib and quantum-pecos (exact-version pins).

Rust API note: PecosError gains a RuntimeUndefinedVariable variant — source-breaking for downstream code that exhaustively matches the enum (0.x pre-release).

What's Changed

• Explore zx by @ciaranra in #272
• Some more RNG Error fixes by @Jonhas-qtm in #270
• exposing stabilizer seeding for the Python wrappers by @ciaranra in #275
• Structure by @ciaranra in #276
• Api polish by @ciaranra in #277
• Bump rustls-webpki from 0.103.9 to 0.103.10 by @dependabot[bot] in #274
• Bump black from 26.3.0 to 26.3.1 by @dependabot[bot] in #268
• Bump tornado from 6.5.4 to 6.5.5 by @dependabot[bot] in #265
• Clifford rz simulators by @ciaranra in #278
• QoL: installation and dev workflow polish by @ciaranra in #279
• Rslib direct deps by @ciaranra in #280
• Cleanup by @ciaranra in #281
• Clean by @ciaranra in #282
• Foreign plugins by @ciaranra in #283
• rust phir classical interp by @ciaranra in #284
• Bump wasmtime from 43.0.0 to 43.0.1 in /python/quantum-pecos/tests/docs/rust_crate by @dependabot[bot] in #286
• Bump wasmtime from 43.0.0 to 43.0.1 in the rust-security group across 1 directory by @dependabot[bot] in #285
• Update setuptools requirement from >=62.6 to >=82.0.1 by @dependabot[bot] in #289
• Update wasmtime requirement from >=13.0 to >=43.0.0 by @dependabot[bot] in #288
• Update maturin requirement from <2.0,>=1.2 to >=1.13.1,<2.0 by @dependabot[bot] in #287
• Simulator optimization branch: GPU density matrix, perf, audits, shar… by @ciaranra in #290
• Surf dems by @qciaran in #293
• Surf dems2 by @ciaranra in #294
• StabMps/StabVec: stabilizer+MPS simulator, Python bindings, Selene pl… by @ciaranra in #295
• Bump jupyterlab from 4.5.6 to 4.5.7 by @dependabot[bot] in #299
• Bump notebook from 7.5.5 to 7.5.6 by @dependabot[bot] in #298
• Update pymdown-extensions requirement from >=10.4 to >=10.21.2 by @dependabot[bot] in #297
• Bump rustls-webpki from 0.103.10 to 0.103.13 in /python/quantum-pecos/tests/docs/rust_crate by @dependabot[bot] in #296
• Bump rustls-webpki from 0.103.12 to 0.103.13 in the rust-security group across 1 directory by @dependabot[bot] in #300
• Bump wasmtime from 43.0.1 to 43.0.2 in the rust-security group across 1 directory by @dependabot[bot] in #304
• Bump mistune from 3.2.0 to 3.2.1 by @dependabot[bot] in #302
• Bump jupyter-server from 2.17.0 to 2.18.0 by @dependabot[bot] in #301
• Cleanup by @ciaranra in #306
• Polish pecos-neo tool builder execution by @ciaranra in #308
• Feat/optional mwpf cmake detection by @ciaranra in #309
• Profile plumbing and pyo3 fixes by @ciaranra in #310
• Polish by @ciaranra in #311
• Bump idna from 3.14 to 3.15 by @dependabot[bot] in #313
• Bump pymdown-extensions from 10.21.2 to 10.21.3 by @dependabot[bot] in #312
• Dem polish by @ciaranra in #314
• Cleanup by @ciaranra in #315
• CI/supply-chain security hardening by @ciaranra in #316
• Drain remaining code-scanning alerts: idna pin, OSV ignores, FFI SAFETY + null-checks by @ciaranra in #317
• Refactor 5 FFI test sites to NonNull / as_ref().expect() for clearer non-null contracts by @ciaranra in #318
• fix: add RNGadvance support to legacy Python CVM by @qartik in #330
• fix: restore custatevec import compatibility by @qartik in #334
• ci: shorten PR workflow critical path by @qartik in #331
• Dep bump by @ciaranra in #322
• Run generated documentation examples in docs CI by @qciaran in #340
• perf: remove coordinator result lock contention by @qartik in #335
• Render signed PHIR registers as two's-complement bits instead of a sign prefix by @ciaranra in #339
• Bump mistune from 3.2.1 to 3.3.0 by @dependabot[bot] in #346
• Default HybridEngine to the Rust classical interpreter, with parity fixes and #345 engine fail-fast by @ciaranra in #347
• Clear post-merge OSV advisories (cxx, Go stdlib, cgmath) by @ciaranra in #349
• Raise the python-core post-merge timeout to 75 minutes by @ciaranra in #350
• Bump Python packages to 0.9.0.dev0 by @ciaranra in #351

Full Changelog: py-0.8.0.dev8...py-0.9.0.dev0

Installing this pre-release

pip install quantum-pecos==0.9.0.dev0
# or with uv (transitive pre-release pins need the flag):
uv pip install --prerelease=allow quantum-pecos==0.9.0.dev0