[panic] Panic 'too many cycle iterations' for recursive star import (original) (raw)

Hi, I'm experiencing the following panic when trying to use construct, (pypi).

Attached is an MRE and the output of RUST_BACKTRACE=1 uvx ty check mre.py -vv.

Issue appears strongly related to #386 , possibly it has something to do with the multiple * imports used in the library?
Also looks somewhat related to #380 and #256 , though at a glance I don't see any relation to generics.

Let me know if there's anything else I can provide to help. 🙏🏻

Details

File: MRE/mre.py

from io import BytesIO

from construct import Float32l

def main(): dummy_io = BytesIO(b"\x00\x00\x00\x00") print(Float32l.parse_stream(dummy_io))

if name == "main": main()

File: MRE/uv.lock

version = 1 revision = 2 requires-python = "==3.13.*"

[[package]] name = "construct" version = "2.10.70" source = { registry = "https://pypi.org/simple" } sdist = { url = "https://files.pythonhosted.org/packages/02/77/8c84b98eca70d245a2a956452f21d57930d22ab88cbeed9290ca630cf03f/construct-2.10.70.tar.gz", hash = "sha256:4d2472f9684731e58cc9c56c463be63baa1447d674e0d66aeb5627b22f512c29", size = 86337, upload-time = "2023-11-29T08:44:49.545Z" } wheels = [ { url = "https://files.pythonhosted.org/packages/b2/fb/08b3f4bf05da99aba8ffea52a558758def16e8516bc75ca94ff73587e7d3/construct-2.10.70-py3-none-any.whl", hash = "sha256:c80be81ef595a1a821ec69dc16099550ed22197615f4320b57cc9ce2a672cb30", size = 63020, upload-time = "2023-11-29T08:44:46.876Z" }, ]

[[package]] name = "construct-mre" version = "0.1.0" source = { virtual = "." } dependencies = [ { name = "construct" }, ]

[package.metadata] requires-dist = [{ name = "construct" }]

File: MRE/pyproject.toml

[project] name = "construct-mre" version = "0.1.0" requires-python = ">=3.13,<3.14" dependencies = ["construct"] [tool.ruff] target-version = "py313"

$ uv sync
$ RUST_BACKTRACE=1 uvx ty check mre.py  -vv
2025-05-19 11:28:15.152214493 WARN ty is pre-release software and not ready for production use. Expect to encounter bugs, missing features, and fatal errors.
2025-05-19 11:28:15.156542092 DEBUG Version: 0.0.1-alpha.5
2025-05-19 11:28:15.156558632 DEBUG Architecture: x86_64, OS: linux, case-sensitive: case-sensitive
2025-05-19 11:28:15.156619544 DEBUG Searching for a project in '/root/MRE'
2025-05-19 11:28:15.156710746 DEBUG Resolving requires-python constraint: `>=3.13, <3.14`
2025-05-19 11:28:15.156720586 DEBUG Resolved requires-python constraint to: 3.13
2025-05-19 11:28:15.156819628 DEBUG Resolving requires-python constraint: `>=3.13, <3.14`
2025-05-19 11:28:15.156826348 DEBUG Resolved requires-python constraint to: 3.13
2025-05-19 11:28:15.156830298 DEBUG Found project at '/'
2025-05-19 11:28:15.156844038 DEBUG Searching for a user-level configuration at `/root/.config/ty/ty.toml`
2025-05-19 11:28:15.156887549 INFO Defaulting to python-platform `linux`
2025-05-19 11:28:15.15690396 INFO Python version: Python 3.13, platform: linux
2025-05-19 11:28:15.15691343 DEBUG Adding first-party search path '/'
2025-05-19 11:28:15.15693106 DEBUG Using vendored stdlib
2025-05-19 11:28:15.15741041 DEBUG Discovering site-packages paths from sys-prefix `/.venv` (`VIRTUAL_ENV` environment variable')
2025-05-19 11:28:15.15742474 DEBUG Attempting to parse virtual environment metadata at '/.venv/pyvenv.cfg'
2025-05-19 11:28:15.157459671 DEBUG Searching for site-packages directory in `sys.prefix` path `/.venv`
2025-05-19 11:28:15.157469611 DEBUG Resolved site-packages directories for this virtual environment are: ["/.venv/lib/python3.13/site-packages"]
2025-05-19 11:28:15.157479201 DEBUG Adding site-packages search path '/.venv/lib/python3.13/site-packages'
2025-05-19 11:28:15.157578523 DEBUG Setting included paths: 1
2025-05-19 11:28:15.157589554 DEBUG Reloading files for project `***`
2025-05-19 11:28:15.157637385 DEBUG Starting main loop
2025-05-19 11:28:15.157645985 DEBUG Waiting for next main loop message.
2025-05-19 11:28:15.157674185 DEBUG Checking project '***'
2025-05-19 11:28:15.159653446 INFO Indexed 1 file(s)
Checking ------------------------------------------------------------ 0/1 files                                                             2025-05-19 11:28:15.159798329 DEBUG Checking file '/root/MRE/mre.py'
2025-05-19 11:28:15.161136276 DEBUG Resolving dynamic module resolutio
error[panic]: Panicked at /root/.cargo/git/checkouts/salsa-e6f3bb7c2a062968/7edce6e/src/function/execute.rs:209:25 when checking `/root/MRE/mre.py`: `exported_names(Id(2017)): execute: too many cycle iterations`
info: This indicates a bug in ty.
info: If you could open an issue at https://github.com/astral-sh/ty/issues/new?title=%5Bpanic%5D, we'd be very appreciative!
info: Platform: linux x86_64
info: Args: ["ty", "check", "mre.py", "-vv"]
info: Backtrace:
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  84: clone

info: query stacktrace:
   0: exported_names(Id(202c))
             at crates/ty_python_semantic/src/semantic_index/re_exports.rs:46
   1: exported_names(Id(2020))
             at crates/ty_python_semantic/src/semantic_index/re_exports.rs:46
   2: exported_names(Id(201e))
             at crates/ty_python_semantic/src/semantic_index/re_exports.rs:46
   3: semantic_index(Id(2017))
             at crates/ty_python_semantic/src/semantic_index.rs:49
   4: global_scope(Id(2017))
             at crates/ty_python_semantic/src/semantic_index.rs:138
   5: member_lookup_with_policy_(Id(2802))
             at crates/ty_python_semantic/src/types.rs:536
   6: infer_definition_types(Id(1401))
             at crates/ty_python_semantic/src/types/infer.rs:148
   7: infer_scope_types(Id(1000))
             at crates/ty_python_semantic/src/types/infer.rs:121
   8: check_types(Id(c00))
             at crates/ty_python_semantic/src/types.rs:84


Found 1 diagnostic
2025-05-19 11:28:15.17109034 WARN A fatal error occurred while checking some files. Not all project files were analyzed. See the diagnostics list above for details.
2025-05-19 11:28:15.17109648 DEBUG Exiting main loop