There is an updated pull request by ologantr against master on the void-packages repository

https://github.com/ologantr/void-packages libtorrent-updates
https://github.com/void-linux/void-packages/pull/36926

libtorrent-rasterbar: update to 2.0.6.
#### Testing the changes
- I tested the changes in this PR: **briefly**

#### Local build testing
- I built this PR locally for my native architecture (x86_64-glibc)

I have mainly tested qbittorrent and is working as expected so far.
The patch that I have created for libtorrent-rasterbar is essentially
a revert of upstream commit https://github.com/arvidn/libtorrent/commit/55bbcdc4321dbcd899f783763d9390ecc3a09850.
Without this revert the generated pkg-config file has a bogus 
`-l-pthread` flag that then makes linking against libtorrent-rasterbar fail.
Please test :)

Edit: Deluge 2.0.5 seems stable with libtorrent-rasterbar 2.x, but some
tests are failing. For now I've disabled them.
https://git.alpinelinux.org/aports/tree/community/deluge/APKBUILD
https://github.com/deluge-torrent/deluge/pull/312 (this seems in some way related)

A patch file from https://github.com/void-linux/void-packages/pull/36926.patch is attached