docker-compose complains about jsonechema version

[Jeronimo Pellegrini <j_p@aleph0.info>]

Hello,

I have installed Guix on a notebook, and also Docker,
and I think I found a problem. I'm not sure, however, wether
it is a problem that fits in the bug-guix list, because it
is not a bug in Guix core; it is a packaging problem (wrong
dependency, likely).

I have included it in this message, but I will post it elsewhere
it this is not the proper place.

Thank you!
J.

PS: this is what happened:

I installed Docker doing

guix install docker docker-cli docker-compose containerd

Then I did the following:


0. added myself to group "docker", and started dockerd as
root.


1. created a small Debian image with the following script:


```
#!/bin/bash

if [ "$EUID" -ne 0 ]
  then echo "Please run as root"
  exit
fi

rm -rf ./chroot-stable
cdebootstrap stable ./chroot-stable http://deb.debian.org/debian > /dev/null
tar -C chroot-stable -c . | docker import - debian-stable-minimal
```

This created a Docker image 'debian-stable-minimal'


2. from debian-stable-minimal, created another image with an
echo server with the folowing Dockerfile:

```
FROM debian-stable-minimal

ENV DEBIAN_FFONTEND=noninteractive

RUN apt update && apt --yes install ncat && apt clean

COPY echo.sh /bin/

ENTRYPOINT ["/bin/echo.sh"]
```

The echo server is this:

```
#!/bin/bash

ncat -l 2000 -k -c 'xargs -n1 echo'
```

I used

```
docker build -t echo .
```
to build the image tagged 'echo'


3. tried to use docker-compose to start the echo server, with the
following docker-compose.yml file:

```
version: "3.7"
services:
        echo:
                image: echo
                networks:
                        - bridge
                ports:
                        - 1111:2000
```

then docker-compose complains that jsonschema is not installed. I
installed it with

```
guix install python-jsonschema
```

and tried again. But at this point, docker-compose complains that the version of jsonschema installed is
not what it expects:

- expected version is <3,>=2.5.1
- installed version is 3.0.1

```
$ docker-compose 
Traceback (most recent call last):
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 574, in _build_master
    ws.require(__requires__)
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 892, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 783, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.ContextualVersionConflict: (jsonschema 3.0.1 (/gnu/store/w0qzc3l0w8i2ikgjrfjhgk9wh07pcn9x-python-jsonschema-3.0.1/lib/python3.7/site-packages), Requirement.parse('jsonschema<3,>=2.5.1'), {'docker-compose'})

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/gnu/store/7kblfjjjlkvy92gmqq0i9fksimcarrih-docker-compose-1.5.2/bin/.docker-compose-real", line 6, in <module>
    from pkg_resources import load_entry_point
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 3088, in <module>
    @_call_aside
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 3072, in _call_aside
    f(*args, **kwargs)
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 3101, in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 576, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 589, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/gnu/store/zm3188ipzi262s0m8bxm24br77yh9pd8-python-3.7.0/lib/python3.7/site-packages/pkg_resources/__init__.py", line 778, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'jsonschema<3,>=2.5.1' distribution was not found and is required by docker-compose
```

There is no older version of jsonschema available in Guix, though.