$ ./compile_network_ios.sh
Fetching https://github.com/yury/FMake
Fetched https://github.com/yury/FMake (1.25s)
Computing version for https://github.com/yury/FMake
error: Dependencies could not be resolved because no versions of 'fmake' match the requirement 0.0.16..<1.0.0 and root depends on 'fmake' 0.0.16..<1.0.0.
error: 'xcfs': binary target 'ios_system' could not be mapped to an artifact with expected name 'ios_system'

Undefined symbols for architecture arm64:
  "_ios_write", referenced from:
      _TerminalWrite in sys_bsd.o
      _dns_ssu_external_match in ssu_external.o
      _readwrite in netcat.o
      _udptest in netcat.o
      _atelnet in netcat.o
      _ping_main in ping.o
      _pinger in ping.o
      ...
  "_ios_fputs", referenced from:
      _version in nslookup.o
      _get_next_command in nslookup.o
      _version in host.o
      _show_usage in host.o
      _connect_timeout in dighost.o
      _hex_dump in dighost.o
      _dig_printmessage in dig.o
      ...
  "_ios_puts", referenced from:
      _nslookup_printmessage in nslookup.o
      _detailsection in nslookup.o
      _nslookup_main in nslookup.o
      _check_for_more_data in dighost.o
      _dig_received in dig.o
  "_ios_fputc", referenced from:
      _dns_rbt_indent in rbt.o
      _isc__mem_stats in mem.o
      _hex_dump in dighost.o
      _lwres_conf_print in lwconfig.o
      _pr_pack in ping.o
      _finish in ping.o
      _pr_iph in ping.o
      ...
  "_ios_fwrite", referenced from:
      _ExitString in utilities.o
      _isc_stdio_write in stdio.o
      _write_public_key in dst_api.o
  "_ios_fflush", referenced from:
      _isc__socket_close in socket.o
      _default_callback in assertions.o
      _default_unexpected_callback in error.o
      _default_fatal_callback in error.o
      _get_next_command in nslookup.o
      _isc__mem_checkdestroyed in mem.o
      _Dump in utilities.o
      ...
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

> Run sudo xcode-select -s /Applications/Xcode_12.3.app
xcode-select: error: invalid developer directory '/Applications/Xcode_12.3.app'