build without flash attn?

[sipie800]

I'm building from source. I have flash attn installed before, which takes long time to build. At installing xformers, I notice it's building flash attn again and long time again, can I just use without flash attn ?
Is that the feature in newer version? if I don't want the flash attn in xformers, which version should I roll back to ?

Nowadays for AI, people are testing tons of different libraries or repo everyday rapidly. Please take consider of that, we can't afford heavy building time in daily work. I believe that's for industry deployment but xformers is meant for research right? Please avoid heavy building as much as possible.

[lw]

We have some logic here to avoid building FlashAttn2 if an existing compatible copy is provided by PyTorch. However we always unconditionally build FlashAttn3.

If you could debug that logic and see why it doesn't work for you we'll happily fix it!