opam install cohttp fails because of camlp4

Question

I'm tyring to install cohttp with opam and I get an error regarding modular-implicits

Here is the stack trace for camlp4

chris@chris-870Z5E-880Z5E-680Z5E:~$ opam install camlp4
The following actions will be performed:
  ∗  install camlp4 4.02.0-1modular-implicits

=-=- Gathering sources =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[camlp4] Archive in cache

=-=- Processing actions -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[ERROR] The compilation of camlp4 failed at "make all".
Processing  1/1: [camlp4: rm]
#=== ERROR while installing camlp4.4.02.0-1modular-implicits ==================#
# opam-version 1.2.2
# os           linux
# command      make all
# path         /home/chris/.opam/core/build/camlp4.4.02.0-1modular-implicits
# compiler     system (4.02.3)
# exit-code    2
# env-file     /home/chris/.opam/core/build/camlp4.4.02.0-1modular-implicits/camlp4-12430-e7966f.env
# stdout-file  /home/chris/.opam/core/build/camlp4.4.02.0-1modular-implicits/camlp4-12430-e7966f.out
# stderr-file  /home/chris/.opam/core/build/camlp4.4.02.0-1modular-implicits/camlp4-12430-e7966f.err
### stdout ###
# [...]
# cp /usr/lib/ocaml/compiler-libs/parsetree.cmi camlp4/import/parsetree.cmi
# cp /usr/lib/ocaml/compiler-libs/outcometree.cmi camlp4/import/outcometree.cmi
# cp /usr/lib/ocaml/compiler-libs/oprint.cmi camlp4/import/oprint.cmi
# cp /usr/lib/ocaml/compiler-libs/toploop.cmi camlp4/import/toploop.cmi
# /usr/bin/ocamlc.opt -c -g -w Z -I camlp4/import -warn-error A-3 -I camlp4/config -I camlp4 -o camlp4/config/Camlp4_config.cmi camlp4/config/Camlp4_config.mli
# /usr/bin/ocamlc.opt -c -g -w a -I camlp4/import -warn-error A-3 -I camlp4/config -I camlp4/boot -o camlp4/boot/Camlp4.cmo camlp4/boot/Camlp4.ml
# + /usr/bin/ocamlc.opt -c -g -w a -I camlp4/import -warn-error A-3 -I camlp4/config -I camlp4/boot -o camlp4/boot/Camlp4.cmo camlp4/boot/Camlp4.ml
# File "camlp4/boot/Camlp4.ml", line 14607, characters 36-58:
# Error: Unbound type constructor Asttypes.implicit_flag
# Command exited with code 2.
### stderr ###
# + echo camlp4/Camlp4.cmo camlp4/Camlp4Top.cmo camlp4/camlp4prof.byte camlp4/mkcamlp4.byte camlp4/camlp4.byte camlp4/camlp4fulllib.cma camlp4/camlp4boot.byte camlp4/camlp4boot.cma camlp4/camlp4r.byte camlp4/camlp4r.cma camlp4/camlp4rf.byte camlp4/camlp4rf.cma camlp4/camlp4o.byte camlp4/camlp4o.cma camlp4/camlp4of.byte camlp4/camlp4of.cma camlp4/camlp4oof.byte camlp4/camlp4oof.cma camlp4/camlp4orf.byte camlp4/camlp4orf.cma camlp4/Camlp4Parsers/Camlp4AstLoader.cmo camlp4/Camlp4Parsers/Camlp4DebugParser.cmo camlp4/Camlp4Parsers/Camlp4GrammarParser.cmo camlp4/Camlp4Parsers/Camlp4ListComprehension.cmo camlp4/Camlp4Parsers/Camlp4MacroParser.cmo camlp4/Camlp4Parsers/Camlp4OCamlOriginalQuotationExpander.cmo camlp4/Camlp4Parsers/Camlp4OCamlParser.cmo camlp4/Camlp4Parsers/Camlp4OCamlParserParser.cmo camlp4/Camlp4Parsers/Camlp4OCamlReloadedParser.cmo camlp4/Camlp4Parsers/Camlp4OCamlRevisedParser.cmo camlp4/Camlp4Parsers/Camlp4OCamlRevisedParserParser.cmo camlp4/Camlp4Parsers/Camlp4OCamlRevisedQuotationExpander.cmo camlp4/Camlp4Parsers/Camlp4QuotationCommon.cmo camlp4/Camlp4Parsers/Camlp4QuotationExpander.cmo camlp4/Camlp4Printers/Camlp4AstDumper.cmo camlp4/Camlp4Printers/Camlp4AutoPrinter.cmo camlp4/Camlp4Printers/Camlp4NullDumper.cmo camlp4/Camlp4Printers/Camlp4OCamlAstDumper.cmo camlp4/Camlp4Printers/Camlp4OCamlPrinter.cmo camlp4/Camlp4Printers/Camlp4OCamlRevisedPrinter.cmo camlp4/Camlp4Filters/Camlp4AstLifter.cmo camlp4/Camlp4Filters/Camlp4ExceptionTracer.cmo camlp4/Camlp4Filters/Camlp4FoldGenerator.cmo camlp4/Camlp4Filters/Camlp4LocationStripper.cmo camlp4/Camlp4Filters/Camlp4MapGenerator.cmo camlp4/Camlp4Filters/Camlp4MetaGenerator.cmo camlp4/Camlp4Filters/Camlp4Profiler.cmo camlp4/Camlp4Filters/Camlp4TrashRemover.cmo
# make: *** [byte] Error 10



=-=- Error report -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
The following actions failed
  ∗  install camlp4 4.02.0-1modular-implicits
No changes have been performed

This is happening on Ubuntu 14.04, how can I get around this strange error that is happening?

EDIT: Relevant info

chris@chris-870Z5E-880Z5E-680Z5E:~$ ocaml -version
The OCaml toplevel, version 4.02.3
chris@chris-870Z5E-880Z5E-680Z5E:~$ opam --version
1.2.2

Answer 1

I would propose to have your ocaml compiler installed by opam ( opam switch 4.02.3 ). It looks your ocaml is located in your system.

Apparently, this comes to an older revision of opam database : opam update may solve it.