libuv @1.44.1 fails to build on Leopard: Undefined symbols: "_posix_spawn_file_actions_addinherit_np"

[barracuda156]

libtool: link: /usr/bin/gcc-4.2 -std=gnu99 -dynamiclib  -o .libs/libuv.1.dylib  src/.libs/libuv_la-fs-poll.o src/.libs/libuv_la-idna.o src/.libs/libuv_la-inet.o src/.libs/libuv_la-random.o src/.libs/libuv_la-strscpy.o src/.libs/libuv_la-threadpool.o src/.libs/libuv_la-timer.o src/.libs/libuv_la-uv-data-getter-setters.o src/.libs/libuv_la-uv-common.o src/.libs/libuv_la-version.o src/unix/.libs/libuv_la-async.o src/unix/.libs/libuv_la-core.o src/unix/.libs/libuv_la-dl.o src/unix/.libs/libuv_la-fs.o src/unix/.libs/libuv_la-getaddrinfo.o src/unix/.libs/libuv_la-getnameinfo.o src/unix/.libs/libuv_la-loop-watcher.o src/unix/.libs/libuv_la-loop.o src/unix/.libs/libuv_la-pipe.o src/unix/.libs/libuv_la-poll.o src/unix/.libs/libuv_la-process.o src/unix/.libs/libuv_la-random-devurandom.o src/unix/.libs/libuv_la-signal.o src/unix/.libs/libuv_la-stream.o src/unix/.libs/libuv_la-tcp.o src/unix/.libs/libuv_la-thread.o src/unix/.libs/libuv_la-tty.o src/unix/.libs/libuv_la-udp.o src/unix/.libs/libuv_la-bsd-ifaddrs.o src/unix/.libs/libuv_la-darwin-proctitle.o src/unix/.libs/libuv_la-darwin.o src/unix/.libs/libuv_la-fsevents.o src/unix/.libs/libuv_la-kqueue.o src/unix/.libs/libuv_la-proctitle.o src/unix/.libs/libuv_la-random-getentropy.o   -L/opt/local/lib -lMacportsLegacySupport  -Os -arch ppc -pthread -Wl,-headerpad_max_install_names -arch ppc   -pthread -install_name  /opt/local/lib/libuv.1.dylib -compatibility_version 2 -current_version 2.0 -Wl,-single_module
Undefined symbols:
  "_posix_spawn_file_actions_addinherit_np", referenced from:
      _uv_spawn in libuv_la-process.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make: *** [libuv.la] Error 1

[evanmiller (Evan Miller)]

In 48a593b172e68600b3de21204c05c387c04b4dcd/macports-ports (master):

libuv: fix build on 10.5/10.6

Closes: #64828