When doing a dir_copy() to an empty destination folder the overwrite parameter produces different results.

In the example below we create the foo dir that contains sub1. Then, we copy foo to newly created destinations dest and dest_overwrite with overwrite = FALSE and overwrite = TRUE respectively. I wouldn't expect the dir tree of the destination folders to defer, however, overwrite parameter affects the nesting of the directories

library(fs)

withr::with_tempdir({
  dir_create("foo")
  dir_create("foo/sub1")

  dir_create("dest")
  dir_copy("foo", "dest", overwrite = FALSE)

  dir_create("dest_overwrite")
  dir_copy("foo", "dest_overwrite", overwrite = TRUE)

  print(dir_tree("dest"))
  print(dir_tree("dest_overwrite"))
})
#> dest
#> └── foo
#>     └── sub1
#> dest/foo      dest/foo/sub1 
#> dest_overwrite
#> └── sub1
#> dest_overwrite/sub1

^{Created on 2024-12-11 with reprex v2.1.0}