utils-yaml.md
In pkgdown: Make Static HTML Documentation for a Package

pkgdown_field produces useful description

Code
  cli::cli_inform(pkgdown_field(pkg, c("a"), cfg = TRUE, fmt = TRUE))
Message
  a in _pkgdown.yml

Code
  check_yaml_has("x", where = "a", pkg = pkg)
Condition
  Error:
  ! Can't find component a.x.
  i Edit _pkgdown.yml to define it.
Code
  check_yaml_has(c("x", "y"), where = "a", pkg = pkg)
Condition
  Error:
  ! Can't find components a.x and a.y.
  i Edit _pkgdown.yml to define them.