PR #182135: [dynamo] Handle typing._GenericAlias in SourcelessBuilder

• Repository: pytorch/pytorch
• Author: huydhn
• State: open | merged: False
• Link: https://github.com/pytorch/pytorch/pull/182135

Description (problem / solution / changelog)

Stack from ghstack (oldest at bottom):

• -> #182135
• #182134

After the pytest 7 -> 9 bump, dynamo_cpython tests started failing on ComplexTest.test_pow with Unsupported: SourcelessBuilder.create does not know how to wrap <class 'typing._GenericAlias'>. pytest 9 added an addSubTest hook to _pytest/unittest.py (pytest 7 had no subTest support at all) whose body is call_info = CallInfo[None](...). CallInfo is a Generic[T] dataclass, and on subscripting it produces a typing._GenericAlias rather than a types.GenericAlias (the PEP 585 runtime form) — only the latter was handled by SourcelessBuilder.create.

CPythonTestCase enables enable_trace_unittest=True and runs with dynamo_strict_nopython=True, so dynamo traces all the way into pytest's addSubTest and the unhandled type is fatal.

Add typing._GenericAlias to the same isinstance branch that already handles types.GenericAlias and types.UnionType. They are conceptually the same surface (a subscripted/parameterised type) and TypingVariable already knows how to handle the value.

Authored with Claude.

cc @voznesenskym @penguinwu @EikanWang @jgong5 @Guobing-Chen @XiaobingSuper @zhuhaozhe @blzheng @wenzhe-nrv @jiayisunx @kadeng @chauhang @amjames @Lucaskabela @jataylo @azahed98

Changed files

• torch/_dynamo/variables/builder.py (modified, +11/-1)