.Rbuildignore has a regular expression on each line, but it's usually easier to work with specific file names. By default, use_build_ignore will (crudely) turn a filename into a regular expression that will only match that path. Repeated entries will be silently removed.

use_build_ignore(files, escape = TRUE)

## Arguments

files Character vector of path names. If TRUE, the default, will escape . to \. and surround with ^ and \$.