【解决】xformers不支持torch2.7.1（cu=11.8的情况）

ERROR: pip's dependency resolver does not currently take into account all the packages that are installed. This behaviour is the source of the following dependency conflicts.
torchvision 0.22.1+cu118 requires torch==2.7.1, but you have torch 2.7.0 which is incompatible.

我看了一下，xformers确实是写了xformers=0.0.30支持2.7.0以上的torch版本，而2.7.1是刚更新的，导致暂时还没有兼容，但是又装不上了2.7.0的torch来匹配对应的cuda=11.8

于是xformers0.0.30暂时舍弃，我们使用xformers==0.0.29

于是先卸载当前torch：

pip uninstall -y torch torchvision

然后安装xformers==0.29需要什么版本的：

 pip install xformers==0.0.29

发现:

ERROR: pip's dependency resolver does not currently take into account all the packages that are installed. This behaviour is the source of the following dependency conflicts.
torchvision 0.22.1+cu118 requires torch==2.7.1, but you have torch 2.5.1 which is incompatible.

于是安装：

pip install torch==2.5.1 torchvision==0.20.1+cu118 torchaudio==2.5.1 --index-url https://download.pytorch.org/whl/cu118

解决！