Re: [Caml-list] Problems installing with opam

[Francois Berenger <francois.berenger@inria.fr>]

On 03/28/2016 01:12 PM, Mr. Herr wrote:
> All (really all?) the opam conf packages are just interfaces to the
> respective OS packages,
> so you would normally need the package plus the dev-package for it.
>
> Just search with apt-cache, apt-file, or command-not-found (beware the
> recursion, the latter two have to be installed :-)
>
> /Str.
>
> On 28.03.2016 05:08, Helmut Brandl wrote:
>> I have severe problems installing some packages with opam. I want to
>> install 'js_of_ocaml' with opam, but it cannot install the package
>> 'conf-pkg-config'. In trying to do this I get the error:
>>
>>     opam install conf-pkg-config
>>     The following actions will be performed:
>>       ∗  install conf-pkg-config 1.0
>>
>>     =-=- Gathering sources
>>     =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>>
>>     =-=- Processing actions
>>     -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>>     [ERROR] The compilation of conf-pkg-config failed at "pkg-config
>>     --help".
>>
>>     #=== ERROR while installing conf-pkg-config.1.0
>>     ===============================#
>>     # opam-version 1.2.2
>>     # os           linux
>>     # command      pkg-config --help
>>     # path /home/helmut/.opam/4.02.3/build/conf-pkg-config.1.0
>>     # compiler     4.02.3
>>     # exit-code    127
>>     # env-file
>>     /home/helmut/.opam/4.02.3/build/conf-pkg-config.1.0/conf-pkg-config-11348-42bb52.env
>>     # stdout-file
>>     /home/helmut/.opam/4.02.3/build/conf-pkg-config.1.0/conf-pkg-config-11348-42bb52.out
>>     # stderr-file
>>     /home/helmut/.opam/4.02.3/build/conf-pkg-config.1.0/conf-pkg-config-11348-42bb52.err
>>
>>
>>
>>     =-=- Error report
>>     -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>>     The following actions failed
>>       ∗  install conf-pkg-config 1.0
>>     No changes have been performed
>>
>>     =-=- conf-pkg-config.1.0 troobleshooting
>>     =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>>     => This package relies on external (system) dependencies that may
>>     be missing. `opam depext conf-pkg-config.1.0' may help you find the
>>        correct installation for your system.
>>
>>
>> The recommended check does not give any information.
>>
>> I have installed the version 4.02.3 successfully via opam and switched
>> to that version.
>>
>> Any ideas on how to analyze the problem?

Did you try what opam told you:

$ opam depext conf-pkg-config

If it does not work, try:

$ opam info --raw conf-pkg-config

This will list you the name of the needed system package for your Linux 
distribution.
Just by the name, I guess it's the package providing the command pkg-config.
If you are using an exotic linux distribution, tell use which one
and we may fix the package conf-pkg-config and even opam depext to work 
with your distribution.

-- 
Regards,
Francois.
"When in doubt, use more types"