This downloads and installs torchaudio version 0.4.0.dev20190801. However, on the given link there are multiple wheels available for a torchaudio 0.4.0 dev version with a later date (all the way up to 20200101). How can I install one of the later versions (preferably the latest one) using pip?
No, when using a completely empty environment and installing torchaudio_nightly using the command above it the latest version pip downloads is 0.4.0-dev20190801, see this Colab notebook. There clearly are torchaudio nightly versions available from a newer data as can be seen on the html nightly link. Conda has a newer version available from this link (v0.4.0.dev20200102).