pair of mutually recursive generic Protocol definitions #1587
Description
I've got a small Python typing showcase (currently using mypy) up at https://github.com/gertvdijk/mypy-sibling-generics-demo. Was wondering how ty would handle/show this, tried it out, but sadly it triggers ty to panic (tested at this current latest commit). It told me to create this bug report, so here I am. 😄
Steps to reproduce: clone that project, and running ty triggers it basically. I believe the output below includes all necessary info, but please LMK if you need anything else or even a smaller MRE.
$ git clone https://github.com/gertvdijk/mypy-sibling-generics-demo.git && cd mypy-sibling-generics-demo
$ uv add --dev ty
$ uv run ty check
error[panic]: Panicked at crates/ty_python_semantic/src/types/instance.rs:822:18 when checking `/path/to/mypy-sibling-generics-demo/foobar/client.py`: `Class wrapped by `Protocol` should be a protocol class`
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: Version: 0.0.1-alpha.27
[...]Full output
error[panic]: Panicked at crates/ty_python_semantic/src/types/instance.rs:822:18 when checking `/path/to/mypy-sibling-generics-demo/foobar/client.py`: `Class wrapped by `Protocol` should be a protocol class`
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: Version: 0.0.1-alpha.27
info: Args: ["ty", "check"]
info: run with `RUST_BACKTRACE=1` environment variable to show the full backtrace information
info: query stacktrace:
0: is_equivalent_to_object_inner(Id(25801))
at crates/ty_python_semantic/src/types/instance.rs:663
cycle heads: infer_definition_types(Id(300e)) -> iteration = 2
1: infer_deferred_types(Id(300b))
at crates/ty_python_semantic/src/types/infer.rs:141
cycle heads: infer_definition_types(Id(300d)) -> iteration = 2, TypeVarInstance < 'db >::lazy_bound_(Id(1c801)) -> iteration = 2
2: TypeVarInstance < 'db >::lazy_bound_(Id(1c800))
at crates/ty_python_semantic/src/types.rs:8734
3: infer_definition_types(Id(300e))
at crates/ty_python_semantic/src/types/infer.rs:94
4: infer_deferred_types(Id(300c))
at crates/ty_python_semantic/src/types/infer.rs:141
5: TypeVarInstance < 'db >::lazy_bound_(Id(1c801))
at crates/ty_python_semantic/src/types.rs:8734
6: infer_definition_types(Id(300d))
at crates/ty_python_semantic/src/types/infer.rs:94
7: infer_scope_types(Id(2400))
at crates/ty_python_semantic/src/types/infer.rs:70
8: check_file_impl(Id(c01))
at crates/ty_project/src/lib.rs:535
error[panic]: Panicked at crates/ty_python_semantic/src/types/instance.rs:822:18 when checking `/path/to/mypy-sibling-generics-demo/foobar/server.py`: `Class wrapped by `Protocol` should be a protocol class`
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: Version: 0.0.1-alpha.27
info: Args: ["ty", "check"]
info: run with `RUST_BACKTRACE=1` environment variable to show the full backtrace information
info: query stacktrace:
0: is_equivalent_to_object_inner(Id(26801))
at crates/ty_python_semantic/src/types/instance.rs:663
cycle heads: infer_definition_types(Id(380d)) -> iteration = 2
1: infer_deferred_types(Id(3808))
at crates/ty_python_semantic/src/types/infer.rs:141
cycle heads: infer_definition_types(Id(380c)) -> iteration = 2, TypeVarInstance < 'db >::lazy_bound_(Id(1e801)) -> iteration = 2
2: TypeVarInstance < 'db >::lazy_bound_(Id(1e800))
at crates/ty_python_semantic/src/types.rs:8734
3: infer_definition_types(Id(380d))
at crates/ty_python_semantic/src/types/infer.rs:94
4: infer_deferred_types(Id(3809))
at crates/ty_python_semantic/src/types/infer.rs:141
5: TypeVarInstance < 'db >::lazy_bound_(Id(1e801))
at crates/ty_python_semantic/src/types.rs:8734
6: infer_definition_types(Id(380c))
at crates/ty_python_semantic/src/types/infer.rs:94
7: infer_scope_types(Id(2800))
at crates/ty_python_semantic/src/types/infer.rs:70
8: check_file_impl(Id(c00))
at crates/ty_project/src/lib.rs:535
Found 2 diagnostics
WARN A fatal error occurred while checking some files. Not all project files were analyzed. See the diagnostics list above for details.