Add an example showing how to build a custom utop with ocamlbuild

README.md

@@ -142,3 +142,6 @@ For example:
 Note that if you are not using ocamlfind, you will need to do that
 yourself. You have to call `Topfind.don't_load` with the list of all
 packages linked with the toplevel.
+
+A full example using ocamlbuild is provided in the
+[examples/custom-utop]() directory.

examples/custom-utop/Makefile

@@ -0,0 +1,7 @@
+OC := ocamlbuild -classic-display -no-links -use-ocamlfind
+
+build:
+	$(OC) -pkg threads,utop -cflag -thread -lflag -thread myutop.top
+
+clean:
+	$(OC) -clean

examples/custom-utop/myutop.mltop

@@ -0,0 +1 @@
+Myutop_main

examples/custom-utop/myutop_main.ml

@@ -0,0 +1,3 @@
+
+(* Start utop. It never returns. *)
+let () = UTop_main.main ()