You have file 'altair/man/altair.Rd' with \docType{package}, likely
intended as a package overview help file, but without the appropriate
PKGNAME-package \alias as per "Documenting packages" in R-exts.
This seems to be the consequence of the breaking change
Using @docType package no longer automatically adds a -package alias.
Instead document _PACKAGE to get all the defaults for package
documentation.
As explained in the issue, to get the desired PKGNAME-package \alias
back, you should either change to the new approach and document the new
special sentinel
From an email from Kurt Hornik: