extractpdfmark build failure on 10.6

[Werner LEMBERG]

Folks,


please have a look at this build log

  https://build.macports.org/builders/ports-10.6_x86_64_legacy-builder/builds/83428

It fails with

  /usr/bin/ranlib: object:
    libextractpdfmark-poppler-core.a(libextractpdfmark_poppler_core_a-pagemode.o)
    malformed object (unknown load command 2)

Searching in the web, I've found a similar report w.r.t. ranlib:

  https://lists.macports.org/pipermail/macports-dev/2018-September/039282.html

It essentially says that `cctools' needs to be installed.  Is this a
dependency that I should add to extrapdfmark's Portfile?  Looking into
other Portfiles, maybe

  platform darwin 10 {
      depends_build-append       port:cctools
  }

is the right fix – is this sufficient to make macports use the newer
`ranlib' binary?

Another issue: extractpdfmark doesn't really need GhostScript for
compilation and execution; however, it will be optionally used for
some `make check' tests.  On the other hand, using the program makes
only sense if the calling Makefile (or whatever) feeds
extractpdfmark's output into GS.  Shall this be somehow reflected in
the Portfile, maybe an `optional dependency'?  If yes, how do I do
that?


    Werner