151785 – net/unison-devel not suitable for parallel build

unison-devel fails to build if MAKE_JOBS_NUMBER is >= 1, for instance,
on multicore computers.  I have set it to MAKE_JOBS_UNSAFE for the
nonce, however, I'd propose that this be fixed. This is usually a sign
that there is a lack of dependency information in the build machinery.

I know too little of OCaML to make more precise statements.

Find below the tail of the log how it fails on my Quadcore computer:

Linking unison-text
ocamlopt -verbose -I lwt -I ubase -o unison-text   unix.cmxa str.cmxa bigarray.cmxa -cclib -lutil ubase/projectInfo.cmx ubase/myMap.cmx ubase/safelist.cmx ubase/uprintf.cmx ubase/util.cmx ubase/rx.cmx ubase/uarg.cmx ubase/prefs.cmx ubase/trace.cmx lwt/pqueue.cmx lwt/lwt.cmx lwt/lwt_util.cmx lwt/lwt_unix.cmx bytearray.cmx case.cmx pred.cmx uutil.cmx fileutil.cmx name.cmx path.cmx fspath.cmx fingerprint.cmx abort.cmx osx.cmx external.cmx props.cmx fileinfo.cmx os.cmx lock.cmx clroot.cmx common.cmx tree.cmx checksum.cmx terminal.cmx transfer.cmx xferhint.cmx remote.cmx globals.cmx copy.cmx stasher.cmx update.cmx files.cmx sortri.cmx recon.cmx transport.cmx strings.cmx uicommon.cmx uitext.cmx test.cmx main.cmx linktext.cmx osxsupport.o pty.o bytearray_stubs.o
+ as -o '/tmp/camlstartup483aff.o' '/tmp/camlstartupca1da4.s'
+ cc -o 'unison-text'   '-Llwt' '-Lubase' '-L/usr/local/lib/ocaml' '/tmp/camlstartup483aff.o' '/usr/local/lib/ocaml/std_exit.o' 'linktext.o' 'main.o' 'test.o' 'uitext.o' 'uicommon.o' 'strings.o' 'transport.o' 'recon.o' 'sortri.o' 'files.o' 'update.o' 'stasher.o' 'copy.o' 'globals.o' 'remote.o' 'xferhint.o' 'transfer.o' 'terminal.o' 'checksum.o' 'tree.o' 'common.o' 'clroot.o' 'lock.o' 'os.o' 'fileinfo.o' 'props.o' 'external.o' 'osx.o' 'abort.o' 'fingerprint.o' 'fspath.o' 'path.o' 'name.o' 'fileutil.o' 'uutil.o' 'pred.o' 'case.o' 'bytearray.o' 'lwt/lwt_unix.o' 'lwt/lwt_util.o' 'lwt/lwt.o' 'lwt/pqueue.o' 'ubase/trace.o' 'ubase/prefs.o' 'ubase/uarg.o' 'ubase/rx.o' 'ubase/util.o' 'ubase/uprintf.o' 'ubase/safelist.o' 'ubase/myMap.o' 'ubase/projectInfo.o' '/usr/local/lib/ocaml/bigarray.a' '/usr/local/lib/ocaml/str.a' '/usr/local/lib/ocaml/unix.a' '/usr/local/lib/ocaml/stdlib.a' '-lbigarray' '-lstr' '-lunix' '-lutil' 'osxsupport.o' 'pty.o' 'bytearray_stubs.o' '/usr/local/lib/ocaml/libasmrun.a' -lm
(if [ -f unison-text ]; then ./unison-text -doc install > INSTALLATION; fi)
gmake: Leaving directory `/usr/ports/net/unison-devel/work/unison-2.32.52'

===>>> Starting check for runtime dependencies
===>>> Gathering dependency list for net/unison-devel from ports
===>>> Dependency check complete for net/unison-devel
===>  Installing for unison-devel-2.32.52_2
===>   Generating temporary packing list
===>  Checking if net/unison-devel already installed
install  -s -o root -g wheel -m 555 /usr/ports/net/unison-devel/work/unison-2.32.52/unison /usr/local/bin
install: /usr/ports/net/unison-devel/work/unison-2.32.52/unison: No such file or directory
*** Error code 71

Stop in /usr/ports/net/unison-devel.

===>>> Installation of unison-devel-2.32.52_2 (net/unison-devel) failed
===>>> Aborting update

===>>> The following actions were performed:
        Installation of lang/ocaml (ocaml-3.11.2)
        Installation of graphics/ocaml-lablgl (ocaml-lablgl-1.04)
        Installation of x11-toolkits/gtkglarea2 (gtkglarea-2.0.1_2)
        Installation of x11-toolkits/ocaml-lablgtk2 (ocaml-lablgtk2-2.14.0_2)

How-To-Repeat: Add FORCE_MAKE_JOBS=yes and MAKE_JOBS_NUMBER=4 to /etc/make.conf
cd /usr/ports/net/unison-devel
make install clean