OCaml Graphics in Mavericks

OCaml graphics relies on X11. Out of the box 10.9 lacks X11. This site provides an ‘Apple approved’ version of X11 called “XQuartz”.

The shell command “ocamlmktop -o mytop graphics.cma” is necessary for OCaml graphics. As shipped it cannot find libX11.6.dylib. as explained here where we propose adding “export DYLD_LIBRARY_PATH=/opt/X11/lib” to the file .bash_profile . In 10.9, however, that addition causes XQuartz to fail.

Here is an awkward workaround:

Disable “export DYLD_LIBRARY_PATH=/opt/X11/lib” in .bash_profile (prefix line with “# ”).
Launch the utility XQuartz. (Dismiss X11 window if you wish.)
Enable “export DYLD_LIBRARY_PATH=/opt/X11/lib” in .bash_profile (remove “# ”.)
Execute shell command “ocamlmktop -o mytop graphics.cma”.
Proceed with new file “mytop” as suggested here.

Perhaps a better workaround: Without the export command in .bash_profile do shell command:

 ocamlmktop -o ~/bin/ocamlg graphics.cma

This should place a top level OCaml interpreter with the graphics functions where the shell command beginning ocamlg launches the interpreter but only in a shell launched while the export command is in .bash_profile.

The following four commands all produce the same error:

ocamlmktop -o mytop graphics.cma
ocamlmktop -o mytop -dllpath /opt/X11/lib graphics.cma
ocamlmktop -o mytop -dllpath /opt/X11 graphics.cma
ocamlmktop -o mytop -dllpath /opt/X11/lib/libX11.6.dylib graphics.cma

The error message is:

File "_none_", line 1:
Error: Error on dynamically loaded library: /usr/local/lib/ocaml/stublibs/dllgraphics.so: dlopen(/usr/local/lib/ocaml/stublibs/dllgraphics.so, 138): Library not loaded: /opt/local/lib/libX11.6.dylib
  Referenced from: /usr/local/lib/ocaml/stublibs/dllgraphics.so
  Reason: image not found

This is useful.