If I fix the UIOP:SUBDIRECTORIES to list both files and directories on CCL, and then filter by which are actually a directories (but this requires checking them with DIRECTORY-EXISTS-P), then the problem disappears. See attached patch.
The question remains though, if UIOP:DIRECTORY-FILES should be modified as well. Currently it will list both files and directories on SBCL and CCL, including symbolic links. However, if a link leads to a directory, SBCL will return a directory pathname for it, whereas on CCL it will be represented as a file pathname.
If I fix the UIOP:SUBDIRECTORIES to list both files and directories on CCL, and then filter by which are actually a directories (but this requires checking them with DIRECTORY- EXISTS- P), then the problem disappears. See attached patch.
The question remains though, if UIOP:DIRECTORY- FILES should be modified as well. Currently it will list both files and directories on SBCL and CCL, including symbolic links. However, if a link leads to a directory, SBCL will return a directory pathname for it, whereas on CCL it will be represented as a file pathname.