unison-2.48 build fails with latest ocaml and flexdll (attn: Achim)

[Andrew Schulman]

> > Then I got a different build error, but
> > I'll ask on the unison list about that.
> 
> Is 2.49 a stable version?  It seems neither Fedora nor Debian have 
> packaged it. 

Hm, you're right. I thought it was the latest beta release, but that's
2.48. Anyway, no need to worry about it here.

> > The build of orpie also failed, but for a different reason. It needed
> > ocaml-camlp4, but when I installed that and tried again I got
> >
> >   ocamlopt.opt -c -pp camlp4o -I ./curses -I ./gsl -I ./units -thread
> > curses_assist.ml
> >   >> Fatal error: OCaml and preprocessor have incompatible versions
> 
> Oops, it seems there were some old curr:/prev: tags on ocaml-camlp4.  I 
> removed those, so please try again with 4.04+1-1.

Build gets farther now, but fails later on complaining about caml__frame:

cd gsl && ocamlc.opt -ccopt "-I/usr/include -I/usr/include/ncurses -ggdb
-O2 -pipe -Wimplicit-function-d
eclaration
-fdebug-prefix-map=/home/ASchulma/dev/cygwin/orpie/orpie-1.5.2-2.x86_64/build=/usr/src/debug/
orpie-1.5.2-2
-fdebug-prefix-map=/home/ASchulma/dev/cygwin/orpie/orpie-1.5.2-2.x86_64/src/orpie-1.5.2=/usr/src/debug/orpie-1.5.2-2
-DHAVE_INLINE -DHAVE_FENV -g -O2" -c mlgsl_matrix_double.c
ml_curses.c:1:0: warning: -fPIC ignored for target (all code is position
independent)
 #include <caml/mlvalues.h>
 ^
In file included from mlgsl_error.c:9:0:
mlgsl_error.c: In function ‘ml_gsl_raise_exn’:
/usr/lib/ocaml/caml/memory.h:236:12: error: ‘caml__frame’ undeclared (first
use in this function)
     (void) caml__frame, \
            ^
/usr/lib/ocaml/caml/memory.h:309:3: note: in expansion of macro
‘CAMLxparam2’
   CAMLxparam2 (x, y)
   ^

This isn't actually a problem now, I was only using orpie as a test. Orpie
hasn't been updated in several years, and the source site has gone dark. So
I may never actually need to build it again. If I do, then I'll have to
solve this.

Thanks for maintaining all the ocaml packages. I see BTW that you added
ocaml-lablgtk2. Some time I'll get back to trying to package Unison with
the GTK2 GUI.

Andrew