Hi Manolis, I just remembered how I addressed it when I cross-built the Hurd with Nix: Given that libc.so is an ld script on GNU/Hurd, simply add libhurduser.so and libmachuser.so in there, next to libc.so.0.3 (see <https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/libraries/glibc/builder.sh#L34>.)
I think it can be a relative file name (so literally “libhurduser.so” would do.) HTH! Ludo’.
