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

https://github.com/skmpz/void-packages fmt-9.0
https://github.com/void-linux/void-packages/pull/38916

fmt: update to 9.0.0.
[ci skip]

Packages bumped and status:
- [x] 0ad: revbumped, built for all archs
- [x] Bear: update to 3.0.20, built for all archs
- [x] cherrytree: revbumped, built for all archs
- [x] coeurl: revbumped, built for all archs
- [ ] cryfs: update to 0.11.2, patches modified (needs boost > 1.75.0)
- [x] easyeffects: revbumped, built for all archs
- [ ] gerbera
- [ ] gnuradio (works with patch)
- [ ] kodi
- [ ] MangoHud
- [ ] mkvtoolnix
- [ ] mpd
- [ ] mtxclient
- [ ] nheko
- [ ] spdlog
- [ ] Waybar


A patch file from https://github.com/void-linux/void-packages/pull/38916.patch is attached