+contain the pathname which caused the problem.
+.Sh VARIANTS
+Defining
+.Dv _DARWIN_C_SOURCE
+or
+.Dv _DARWIN_BETTER_REALPATH
+before including stdlib.h will cause the provided implementation of
+.Fn realpath
+to use F_GETPATH from
+.Xr fcntl 2
+to discover the path.