Fix bug when a directory with the right name appears in the PATH
Fix bug when a directory with the right name appears in the PATH

See https://github.com/ocaml/opam-repository/issues/1306

gerdstolpmann/oasis,gerdstolpmann/oasis,jpdeplaix/oasis,Chris00/oasis,RadicalZephyr/oasis,jpdeplaix/oasis,gerdstolpmann/oasis,madroach/oasis,Chris00/oasis,jpdeplaix/oasis,RadicalZephyr/oasis,madroach/oasis,diml/oasis,Chris00/oasis,diml/oasis