opam

mad@New-Haven ~> opam install utop --use-internal-solver
The following actions will be performed:
  ∗  install lwt         3.1.0                [required by utop]
  ∗  install lwt_react   1.1.0                [required by lambda-term]
  ∗  install lambda-term 1.11                 [required by utop]
  ∗  install utop        2.0.1
===== ∗  4 =====
Do you want to continue ? [Y/n] y

=-=- Gathering sources =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[lambda-term] Archive in cache
[lwt] Archive in cache
[lwt_react] Archive in cache
[utop] Archive in cache

=-=- Processing actions -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[ERROR] The compilation of lwt failed at "jbuilder build -p lwt -j 4".

#=== ERROR while installing lwt.3.1.0 =========================================#
# opam-version 1.2.2
# os           linux
# command      jbuilder build -p lwt -j 4
# path         /home/mad/.opam/system/build/lwt.3.1.0
# compiler     system (4.05.0)
# exit-code    1
# env-file     /home/mad/.opam/system/build/lwt.3.1.0/lwt-13875-d2c37b.env
# stdout-file  /home/mad/.opam/system/build/lwt.3.1.0/lwt-13875-d2c37b.out
# stderr-file  /home/mad/.opam/system/build/lwt.3.1.0/lwt-13875-d2c37b.err
### stderr ###
# [...]
# found config var system: ....................... linux
# found config var os_type: ...................... Unix
# found config var use_libev: .................... false
# not checking for pkg-config
#
# Error: failed to compile a trivial ocaml toplevel.
# You may be missing core components (compiler, ncurses, etc)
#
# Run with DEBUG=y for more details.
#



=-=- Error report -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
The following actions were aborted
  ∗  install lambda-term 1.11
  ∗  install lwt_react   1.1.0
  ∗  install utop        2.0.1
The following actions failed
  ∗  install lwt 3.1.0
No changes have been performed

=-=- lwt.3.1.0 troubleshooting =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
=> Lwt 4.0.0 will make some breaking changes to packaging in late 2017. See
     https://github.com/ocsigen/lwt/issues/453