requiring torch >= 1.7.1

[danpovey]

why does lhotse require torch >= 1.7.1?
just curious. I was using 1.7.0.

[pzelasko]

The "1.7" part is because that's the first version where torchaudio has the sox_effects module. I am not sure about the .1 patch -- but I think it was arbitrary and not related to any specific issue that they fixed. I can probably lower the required version.

[mthrok]

@pzelasko PyTorch 1.7 (==torchaudio 0.7) had issue with OpenMP and sox_effects, where sox_effects becomes super slow. We disabled the OpenMP for sox_effects in PyTorch 1.7.1 (==torchaudio 0.7.2)

[pzelasko]

Ah, of course, I remember now 🤦🏼. Thanks!

[mthrok]

The issue was reported here pytorch/audio#1021

[danpovey]

BTW, I had some difficulty installing the latest version of Lhotse.
The torch wheel files are quite slow to download here so I wanted to us a version of torch (1.7.1) that I believed would work, that Lhotse accepted, and we had the wheel file for locally.
But then Lhotse noticed that the torchaudio version was not sufficient, either below Lhotse's requirement or incompatible with this torch, so it decided to download a more recent version of torchaudio. It chose the most recent version. For this it tried pulling in a more recent version of torch (1.9.x). I wanted to find a torchaudio version that was compatible with the 1.7.1 of torch, but it turns out that that is a very nontrivial thing to do, since pip currently offers no mechanism to find out what the requirements of a given version of a package are without actually installing it (an unforgivable omission). I found a package called johnnydep which appears to be able to do that (at the expense of downloading the wheel files concerned).

I'm guessing there are no easy fixes for these problems, because they are weaknesses in pip itself, and trying to fix upstream problems is often not a good idea.

[pzelasko]

Sorry to hear that. FWIW anaconda/miniconda would have probably downloaded the right torchaudio, they are more strict about the version compatibility. I think the right torchaudio is 0.7.2 but not sure how I came to know that.

EDIT: Moto mentioned it a few comments above and my subconsious remembered ;)

[pzelasko]

Resolved by #348