Linking error: undefined _dprintf, _vdprintf

[barracuda156]

@rahra Logging-related commit https://github.com/rahra/onioncat/commit/a75bc8e2ebc447bb657080213803436631803f33 has broken the build on some systems:

/usr/bin/gcc-4.2 -std=gnu99 -DSYSCONFDIR=\"/opt/local/etc\" -DSTATEDIR=\"/opt/local/var/onioncat\" -pipe -Os -arch ppc -Wall -Wextra -O2 -pthread  -L/opt/local/lib -Wl,-headerpad_max_install_names -arch ppc -o ocat ocat.o ocatlog.o ocatroute.o ocatthread.o ocattun.o ocatv6conv.o ocatcompat.o ocatpeer.o ocatsetup.o ocatipv4route.o ocateth.o ocatsocks.o ocatlibe.o ocatctrl.o ocatipv6route.o ocaticmp.o ocat_wintuntap.o ocat_netdesc.o ocathosts.o ocatresolv.o ocatfdbuf.o  -lpthread 
Undefined symbols for architecture ppc:
  "_dprintf", referenced from:
      _mk_pid_file in ocat.o
      _vlog_msgf in ocatlog.o
      _log_msg_fd in ocatlog.o
      _print_setup_struct in ocatsetup.o
      _ipv4_print in ocatipv4route.o
      _print_mac_tbl in ocateth.o
      _socks_output_queue in ocatsocks.o
      ...
  "_vdprintf", referenced from:
      _vlog_msgf in ocatlog.o
      _log_msg_fd in ocatlog.o
ld: symbol(s) not found for architecture ppc
collect2: ld returned 1 exit status

Can a fallback be added?

[rahra]

Checkout and compile the development branch. The latest commit c05e82073d4abdd35736695e7c017c039ef0316a should do it.