-perl 5.8.0 sets C<$^X> where possible to a full path by asking the operating
-system. On FreeBSD the full path of the perl interpreter is found by reading
-the symlink F</proc/curproc/file>. There is a bug on FreeBSD, where the
-result of reading this symlink is can be wrong in certain circumstances
+perl sets C<$^X> where possible to a full path by asking the operating
+system. On FreeBSD the full path of the perl interpreter is found by using
+C<sysctl> with C<KERN_PROC_PATHNAME> if that is supported, else by reading
+the symlink F</proc/curproc/file>. FreeBSD 7 and earlier has a bug where
+either approach sometimes returns an incorrect value