Merge branch 'ab5tract-inc'

Author: jonathanstowe

bin/p6doc-index

@@ -29,6 +29,7 @@ multi sub MAIN('build') {
     # XXX p6doc probably uses another path to @*INC which is probably incomplete
 
     for @*INC.map({CompUnitRepo.new($_)})».IO -> $lib_path is copy {
+        next unless $lib_path.e;
 
         $lib_path = $lib_path.Str;
         my @files :=  find(:dir($lib_path),:type('file'));