The pkgver variable is set to GE_Proton10_5. This version is not available anymore from the Github repository. GE_Proton10_6 is, as is GE_Proton10_7 (the current version).
I'm not sure how the bot pulls merged PR into this package, but it might require a little tweaking?
Pinned Comments
PedroHLC commented on 2021-07-27 19:39 (UTC)
The "chaotic-aur" co-maintainer is a bot that pulls any merged PR in https://github.com/chaotic-aur/pkgbuild-proton-ge-custom-bin back to this package. So if you guys have contributions or bump versions earlier than the maintainer, please share them as PRs. The commits will keep your authorship.
Happy gaming!