Version constraints on the required ONNX modules are too strong.

[RyusukeYamano]

The ONNX module version constraint is too strong, so pip installation may not be able to resolve dependencies with other modules.
The problem is especially likely to occur when adding learning modules such as pytorch.

[Shinya T-Y]

I agree. Now I'm using onnx==1.9.0 in my test environment.

[RyusukeYamano]

Sounds like great!

[Shinya T-Y]

The dependent version is changed in 7ef5b48 .