Docker build with `opam install ocaml-migrate-parsetree` fails

[ryyppy]

Hi!

I created a basic OCaml Docker image with an installed OCaml compiler 4.06.0 and opam 1.2.2.

I based off a Dockerfile which installs ocaml-migrate-parsetree like this:

FROM ryyppy/ocaml:4.06.0

RUN opam install ocaml-migrate-parsetree || true

docker build -t my-ocaml -f Dockerfile . does yield following error messages during the build:

Step 1/2 : FROM ryyppy/ocaml:4.06.0
 ---> 9fd61c178361
Step 2/2 : RUN opam install ocaml-migrate-parsetree || true
 ---> Running in 9126211b07a3
The following actions will be performed:
  - install ocaml-migrate-parsetree 1.0.11

=-=- Gathering sources =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[ocaml-migrate-parsetree: from default] Command started
[ocaml-migrate-parsetree: from default] Command started
[default] https://opam.ocaml.org/archives/ocaml-migrate-parsetree.1.0.11+opam.tar.gz downloaded

=-=- Processing actions -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
[ocaml-migrate-parsetree: jbuilder build] Command started
[ERROR] The compilation of ocaml-migrate-parsetree failed at "jbuilder build -p
        ocaml-migrate-parsetree -j 4".

#=== ERROR while installing ocaml-migrate-parsetree.1.0.11 ====================#
# opam-version         1.2.2
# os                   linux
# command              jbuilder build -p ocaml-migrate-parsetree -j 4
# path                 /home/opam/.opam/system/build/ocaml-migrate-parsetree.1.0.11
# compiler             system (4.06.0)
# exit-code            127
# env-file             /home/opam/.opam/system/build/ocaml-migrate-parsetree.1.0.11/ocaml-migrate-parsetree-5-ad8886.env
# stdout-file          /home/opam/.opam/system/build/ocaml-migrate-parsetree.1.0.11/ocaml-migrate-parsetree-5-ad8886.out
# stderr-file          /home/opam/.opam/system/build/ocaml-migrate-parsetree.1.0.11/ocaml-migrate-parsetree-5-ad8886.err



=-=- Error report -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
The following actions failed
  - install ocaml-migrate-parsetree 1.0.11
No changes have been performed
Removing intermediate container 9126211b07a3
 ---> 509f962534b6
Successfully built 509f962534b6
Successfully tagged my-ocaml:latest

I entered the container and looked into the resulting .out and .err files, but they are empty.

Another interesting thing: When I run the original docker image and do the opam install command in interactive mode, it works just fine.

Any ideas how to fix this?

[ryyppy]

Alright, this wasn't an issue with ocaml-migrate-parsetree itself, but more of a path finding problem with jbuilder

Just for those who are stuck with this (specifically trying to install reason via Dockerfile), source the opam env in the RUN command first:

RUN eval `opam config env` && opam install ocaml-migrate-parsetree

With this in place, jbuilder can be found in the path and the package can do its build procedure.