KIO extras fail to configure because of absense of xdr_u_int64_t in RPC. As far as I found, that's due to deprecation of rpc part in modern Glibc. I also think that the problem is connected to this review: https://git.reviewboard.kde.org/r/120969/. I've added includes of headers from libtirpc, NFS kio seems to build and work fine. Perhaps, it makes sense to migrate it to libtirpc completely for GNU/Linux. Reproducible: Always
Believed fixed, kio_nfs compiles with current Glibc using TIRPC. Please reopen if there are still build problems on any particular platform.