MarsSeed  filed a deletion request for kubesec :
Orphaned package. The application itself is legacy. Last release happened in 2018; last commit was in 2019.
This was a security module for Kubernetes, to manage 'secrets' (token keys, passwords, etc.) for cloud instances.
The build is broken because of problems in the PKGBUILD itself. Also the code uses the now deprecated Golang Glide dependency manager.
I think it's safe to assume that cloud security related management tools should be kept up-to-date, or otherwise cannot be trusted.
'Secrets' management is one of the central concepts and features of Kubernetes cloud management/instrumentation platform. Therefore I am certain that there do exist currently supported and maintained toolkits for such use cases and this old application is not needed anymore.
It might be possible to make it build again but IMHO it's not worth the hassle, on the merits of the points above.
Nothing depends on this on AUR so it's safe to delete.