No attribute error when writing to a builtin defined in builtins.pyi

[Wizzerinus]

Describe the Bug

With the following files:

~/t/pyrefly_builtins $ cat test.py                                             
import builtins
print(globalVar)
builtins.globalVar=1

~/t/pyrefly_builtins $ cat __builtins__.pyi                               
globalVar: int

globalVar is correctly inferred as an int in the second line, but the third line emits an error

Sandbox Link

https://pyrefly.org/sandbox/?project=v2.pZRBDoQgDEWv0sQFOzuz9RRzgNngjEESIkbQ8_spYqKJbtwWWsp_7b-yzG3z2tm6iDlJsmd5jfOtdnAtQVHO6z2MLt8v6e-kTkWfHKDtIfgCZDUz3Ady1d-hgvF01Mc4hoa5pPvJcDfw3_8CHzKY0iDoRVvxtGM58kIzoOwTLCpTUXdQVGKCG0KhCCIkLL69C9NgXOMtixU

(Only applicable for extension issues) IDE Information

No response

[rchen152]

@Wizzerinus May I ask what your use case is for this? This does look potentially like a bug in pyrefly, but needing to inject a custom builtins stub and furthermore patch it at runtime is pretty unusual, and I'm wondering if there's an issue with upstream builtins.pyi or something related that we should fix instead/in addition to this.

[Wizzerinus]

There are several libraries that make use of builtins, the two I'm aware of are Panda3D and Databricks. To use custom builtins, they have to be set somewhere initially, and trying to do so currently emits an error.