Error: Signature mismatch: "compiler/libqmlcompil/dbGen/schema_io.ml"

[zoowar]

I cloned opa source today and the build failed.

The OCaml toplevel, version 4.00.1

Ocamlbuild generation
_build/myocamlbuild.exe -no-plugin -j 6 -tag debug opabsl.qmljs.stamp plugins.qmljs.stamp ocamllib/libbase/bslServerLib.ml tools/odeplink.native tools/teerex/trx_ocaml.native compiler/pplib/ppml.native tools/jschecker/compiler.jar compiler/opalang/opa2opa.native tools/teerex/trx_interpreter.native tools/dissemination/spawn.sh tools/ofile.native compiler/libbsl/bslregister.native compiler/opa/gen_opa_manpage.native compiler/libbsl/bslbrowser.native compiler/libbsl/bslbrowser compiler/passlib/passdesign.native compiler/passlib/opatrack.sh compiler/opa/syntaxHelper.native compiler/compilerlib/opadep.sh tools/manpages/genman.native compiler/opa/checkopacapi.native ocamllib/libbase/testfilepos.native compiler/main.native compiler/jslang/jsstat.native compiler/opx2js/opx2js.native compiler/jslang/globalizer.native compiler/pplib/ppopa.native tools/bash/bash_completion compiler/qmlcompilers/qmljs_exe.native compiler/pplib/ppjs.native lib/plugins/opabsl/serverLib.cmi tools/odep.native ocamllib/libbase/gen_platform opa-node-packages.stamp qmljs.opa.create
+ /usr/bin/ocamlc.opt -c -g -warn-error A -w L -w Z -I /usr/lib64/ocaml/ocamlgraph -I ocamllib/libbase -I compiler/buildinfos -I compiler/compilerlib -I compiler/libtrx -I compiler/opacapi -I compiler/passlib -I compiler/libqmlcompil -I compiler/libqmlcompil/typer_w -I compiler/libqmlcompil/dbGen -I ocamllib -I compiler -I lib -I tools -I tools/build -o compiler/libqmlcompil/dbGen/schema_io.cmo compiler/libqmlcompil/dbGen/schema_io.ml
File "compiler/libqmlcompil/dbGen/schema_io.ml", line 86, characters 38-47:
Error: Signature mismatch:
       ...
       Values do not match:
         val vertex_attributes :
           V.t ->
           [> `Comment of string
            | `Label of string
            | `Shape of [> `Box | `Circle | `Doublecircle ]
            | `Style of [> `Bold | `Solid ] ]
           list
       is not included in
         val vertex_attributes :
           V.t -> Graph.Graphviz.DotAttributes.vertex list
       File "compiler/libqmlcompil/dbGen/schema_io.ml", line 55, characters 6-23:
         Actual declaration
Command exited with code 2.
Compilation unsuccessful after building 832 targets (0 cached) in 00:00:30.

[hbbio]

You need ocamlgraph 1.8.5 or greater.