Hello,

On the 'core-updates' branch, using copy-recursively on a nonexistent
directory does not cause a build failure.  Instead an error is printed
and the script continues:

  (copy-recursively "doesnotexist" output)
  [...]
  starting phase `install'
  i/o error: doesnotexist: No such file or directory
  phase `install' succeeded after 0.0 seconds

This is on cc6cb6e80a42355147809b4830053a34d1563994.