I have seen that it is listed as unmaintained, but perhaps it is useful to track what specifically fails.
ocamlc -w +a-3-4-6-27-29-32-35-37-41-44-45-48-60-70 -I src/utils/extlib -I src/utils/cdk -I src/utils/bitstring -I src/utils/lib -I src/utils/ocamlrss -I src/utils/xml-light -I src/utils/net -I tools -I src/daemon/common -I src/daemon/driver -I src/utils/mp3tagui -I src/config/unix -I src/gtk2/gui -I src/gtk2/gui/x11 -I src/gtk2/gui/win32 -I icons/rsvg -I +lablgtk2 -I src/networks/direct_connect -I src/networks/gnutella2 -I src/networks/fasttrack -I src/networks/fileTP -I src/networks/bittorrent -I src/networks/donkey -I +camlp4 -I /opt/local/lib/ocaml/site-lib/num -c src/networks/gnutella2/g2Proto.ml
File "src/networks/gnutella2/g2Proto.ml", line 925, characters 11-12:
925 | (s, ip, port, !udp_counter, 0, last_time () + 10, ref false);
^
Error: This expression has type string but an expression was expected of type
bytes
gmake: *** [Makefile:5447: src/networks/gnutella2/g2Proto.cmo] Error 2