Installing lablgtk failed; cannot find camlp4orf.

Installing lablgtk failed.
It appears to be unable to find camlp4orf.
Any ideas?

-- hendrik


hendrik@notlookedfor:~/dv/ocaml/learngtk$ opam install lablgtk
The following actions will be performed:
 - install   camlp4.4.01+system                    [required by lablgtk]
 - install   lablgtk.2.18.3
=== 2 to install ===
Do you want to continue ? [Y/n] y

=-=- Synchronizing package archives -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

=-=- Installing packages =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Copying ~/.opam/repo/default/packages/camlp4/camlp4.4.01+system/files/install to ~/.opam/system/build/camlp4.4.01+system/
Copying ~/.opam/repo/default/packages/camlp4/camlp4.4.01+system/files/check-camlp4.sh to ~/.opam/system/build/camlp4.4.01+system/
Building camlp4.4.01+system:
  sh ./check-camlp4.sh
[ERROR] The compilation of camlp4.4.01+system failed.
Removing camlp4.4.01+system.
  Nothing to do.
[WARNING] Directory /home/hendrik/.opam/system/lib/camlp4 is not empty, not removing


#=== ERROR while installing camlp4.4.01+system ================================#
# opam-version 1.2.0
# os           linux
# command      sh ./check-camlp4.sh
# path         /home/hendrik/.opam/system/build/camlp4.4.01+system
# compiler     system (4.01.0)
# exit-code    1
# env-file     /home/hendrik/.opam/system/build/camlp4.4.01+system/camlp4-8311-c61e7b.env
# stdout-file  /home/hendrik/.opam/system/build/camlp4.4.01+system/camlp4-8311-c61e7b.out
# stderr-file  /home/hendrik/.opam/system/build/camlp4.4.01+system/camlp4-8311-c61e7b.err
### stdout ###
# ...[truncated]
# `opam switch`.
# 
# Here are some installation instructions for camlp4 if you obtained OCaml
# via the OPAM binary packages:
# 
# http://software.opensuse.org/download.html?project=home%3Aocaml&package=ocaml
# 
# * Debian/Ubuntu: sudo apt-get install camlp4-extra
# * RHEL/CentOS/Fedora: sudo yum install ocaml-camlp4
# 
### stderr ###
# ./check-camlp4.sh: 3: ./check-camlp4.sh: camlp4orf: not found


=-=- Error report -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
The following failed
 - install   camlp4.4.01+system
Due to the errors, the following have been cancelled
 - install   lablgtk.2.18.3
hendrik@notlookedfor:~/dv/ocaml/learngtk$