dongcarl@ /u/h/dongcarl> opam install mirage
The following actions will be performed:
  ∗  install cmdliner         0.9.7           [required by mirage]
  ∗  install ocamlfind        1.5.5           [required by lwt, ipaddr, mirage-types-lwt]
  ∗  install camlp4           4.02+system     [required by lwt]
  ∗  install ppx_tools        0.99.2          [required by lwt]
  ∗  install cppo             1.1.2           [required by ocplib-endian]
  ∗  install base-bytes       base            [required by ipaddr]
  ∗  install type_conv        112.01.02       [required by ipaddr]
  ∗  install lwt              2.5.0           [required by mirage]
  ∗  install ocplib-endian    0.8             [required by cstruct]
  ∗  install sexplib          112.35.00       [required by ipaddr]
  ∗  install ipaddr           2.6.1           [required by mirage]
  ∗  install cstruct          1.7.0           [required by mirage-types-lwt]
  ∗  install io-page          1.5.1           [required by mirage-types-lwt]
  ∗  install mirage-types     2.3.0           [required by mirage-types-lwt]
  ∗  install mirage-types-lwt 2.3.0           [required by mirage]
  ∗  install mirage           2.5.0
===== ∗  16 =====
Do you want to continue ? [Y/n] y

=-=- Gathering sources =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[default] https://opam.ocaml.org/archives/cppo.1.1.2+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/cstruct.1.7.0+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/io-page.1.5.1+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/ipaddr.2.6.1+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/cmdliner.0.9.7+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/mirage.2.5.0+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/mirage-types.2.3.0+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/ocplib-endian.0.8+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/ppx_tools.0.99.2+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/lwt.2.5.0+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/ocamlfind.1.5.5+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/type_conv.112.01.02+opam.tar.gz downloaded
[default] https://opam.ocaml.org/archives/sexplib.112.35.00+opam.tar.gz downloaded

=-=- Processing actions -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[ERROR] The compilation of camlp4 failed at "sh ./check-camlp4.sh".
∗  installed cmdliner.0.9.7
∗  installed ocamlfind.1.5.5
∗  installed base-bytes.base
∗  installed cppo.1.1.2
∗  installed ppx_tools.0.99.2
∗  installed ocplib-endian.0.8

#=== ERROR while installing camlp4.4.02+system ================================#
# opam-version 1.2.2
# os           freebsd
# command      sh ./check-camlp4.sh
# path         /home/dongcarl/.opam/system/build/camlp4.4.02+system
# compiler     system (4.02.1)
# exit-code    1
# env-file     /home/dongcarl/.opam/system/build/camlp4.4.02+system/camlp4-72839-487c34.env
# stdout-file  /home/dongcarl/.opam/system/build/camlp4.4.02+system/camlp4-72839-487c34.out
# stderr-file  /home/dongcarl/.opam/system/build/camlp4.4.02+system/camlp4-72839-487c34.err
### stdout ###
# [...]
# 4.02 by switching to a local installation via `opam switch 4.02.0`.
#
# 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: camlp4orf: not found



=-=- Error report -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
The following actions were aborted
  ∗  install cstruct          1.7.0
  ∗  install io-page          1.5.1
  ∗  install ipaddr           2.6.1
  ∗  install lwt              2.5.0
  ∗  install mirage           2.5.0
  ∗  install mirage-types     2.3.0
  ∗  install mirage-types-lwt 2.3.0
  ∗  install sexplib          112.35.00
  ∗  install type_conv        112.01.02
The following actions failed
  ∗  install camlp4 4.02+system
The following changes have been performed
  ∗  install base-bytes    base
  ∗  install cmdliner      0.9.7
  ∗  install cppo          1.1.2
  ∗  install ocamlfind     1.5.5
  ∗  install ocplib-endian 0.8
  ∗  install ppx_tools     0.99.2

The former state can be restored with:
    opam switch import "~/.opam/system/backup/state-20150612040613.export"