ERROR while compiling mccs.1.1+9

[freedog8]

[jliu@login01 PhyloCSF]$ opam pin add opam-devel --dev
[NOTE] Package opam-devel is already pinned to git+https://github.com/ocaml/opam.git (version 2.0.0).
[opam-devel.2.0.0] no changes from git+https://github.com/ocaml/opam.git
[WARNING] Failed checks on opam-devel package definition from source at git+https://github.com/ocaml/opam.git:
    error 57: Synopsis and description must not be both empty
opam-devel is now pinned to git+https://github.com/ocaml/opam.git (version 2.0.0)

The following actions will be performed:
  ∗ install mccs        1.1+9  [required by opam-solver]
  ∗ install opam-solver 2.0.0  [required by opam-client]
  ∗ install opam-client 2.0.0  [required by opam-devel]
  ∗ install opam-devel  2.0.0*
===== ∗ 4 =====
Do you want to continue? [Y/n] Y

<><> Gathering sources ><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[mccs.1.1+9] found in cache
[opam-client.2.0.0] found in cache
[opam-solver.2.0.0] found in cache

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[ERROR] The compilation of mccs failed at "/data/gpfs01/jliu/.opam/default/bin/jbuilder build -p mccs".

\#=== ERROR while compiling mccs.1.1+9 =========================================#
\# context     2.0.0 | linux/x86_64 | ocaml-base-compiler.4.07.1 | https://opam.ocaml.org#a06304aa
\# path        ~/.opam/default/.opam-switch/build/mccs.1.1+9
\# command     ~/.opam/default/bin/jbuilder build -p mccs
\# exit-code   1
\# env-file    ~/.opam/log/mccs-23215-548b09.env
\# output-file ~/.opam/log/mccs-23215-548b09.out
\### output ###
\# [...]
\# Called from file "map.ml", line 295, characters 20-25
\# Called from file "src/gen_rules.ml", line 239, characters 4-25
\# Called from file "map.ml", line 295, characters 20-25
\# Called from file "src/gen_rules.ml", line 313, characters 2-60
\# Called from file "src/fiber/fiber.ml", line 111, characters 22-27
\# Called from file "src/fiber/fiber.ml", line 299, characters 6-13
\#
\# I must not segfault.  Uncertainty is the mind-killer.  Exceptions are
\# the little-death that brings total obliteration.  I will fully express
\# my cases.  Execution will pass over me and through me.  And when it
\# has gone past, I will unwind the stack along its path.  Where the
\# cases are handled there will be nothing.  Only I will remain.



<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
┌─ The following actions failed
│ λ build mccs 1.1+9
└─
╶─ No changes have been performed
[NOTE] Pinning command successful, but your installed packages may be out of sync.

[rjbou]: edit format

[rjbou]

It is an internal error that affect mccs compilation. I report it here ocaml/dune#734 (comment).
A workaround is to pin dune to 1.5.1 (the error appears in 1.6.0).
Thanks for reporting!

[rjbou]

There is a new release of dune 1.6.2 that fixes it, and mccs opam file has been updated too. You just need to update your repo!