Owfs fails to compile when configured with --disable-ha7 option. The problem affects 2.8_p20, 2.8_p21 and possibly older versions.
The attached patch adds missing #ifdefs in files ow_enet_discover.c and ow_server_enet.c. It also removes empty ENET_monitor_detect() declaration from ow_enet_monitor.c when OW_HA7 is not defined, which seems to be unnecessary as the only reference was in ow_server_enet.c.
Thank you for the patch, but I'm not sure it's still needed. --disable-ha7 was removed entirely in the newest version (2.9p0).