I'm want to build a test environment using Docker. I followed the steps described at Getting started with Decidim at Github especially the following:

To get started, first clone the decidim repo

git clone https://github.com/decidim/decidim: DONE

Switch to the cloned folder

cd decidim: DONE

Then create a development application

d/bundle install: FAILED



Logging of Terminal (root@):

git clone https://github.com/decidim/decidim

Cloning into 'decidim'...

remote: Enumerating objects: 60, done.

remote: Counting objects: 100% (60/60), done.

remote: Compressing objects: 100% (51/51), done.

remote: Total 161826 (delta 19), reused 0 (delta 0), pack-reused 161766

Receiving objects: 100% (161826/161826), 97.64 MiB | 12.57 MiB/s, done.

Resolving deltas: 100% (97672/97672), done.

Updating files: 100% (9074/9074), done.



d/bundle install

Creating decidim_redis_1 ... done

Creating decidim_pg_1  ... done

Pulling decidim (decidim/decidim:latest-dev)...

latest-dev: Pulling from decidim/decidim

57df1a1f1ad8: Pull complete

71e126169501: Pull complete

1af28a55c3f3: Pull complete

03f1c9932170: Pull complete

65b3db15f518: Pull complete

1226ce1a6914: Pull complete

6e7d578ece6c: Pull complete

478e41df9116: Pull complete

0d6a4f30c46b: Pull complete

7a77586c4424: Pull complete

c23550da75b5: Pull complete

76404f8eb02c: Pull complete

b3ca8228e263: Pull complete

3d26f180b974: Pull complete

740d5fac8d94: Pull complete

21b2b3a539b2: Pull complete

c1df0b819c5a: Pull complete

bcb27b0ea2e6: Pull complete

4ab0003f1a1c: Pull complete

e5e519d67a6c: Pull complete

0f223c741843: Pull complete

9adfb4cedc32: Pull complete

Digest: sha256:86601239400940b8c75beff17b09a0b99982d6852c5a5677a77b887c0f8cfe04

Status: Downloaded newer image for decidim/decidim:latest-dev

^[[B^[[B^[[C^[[C^[[D^[[D^[[D+ stat -c %u /code/Gemfile

+ USER_UID=0

+ stat -c %g /code/Gemfile

+ USER_GID=0

+ export USER_UID

+ export USER_GID

+ usermod -u 0 decidim

+ groupmod -g 0 decidim

+ usermod -g 0 decidim

+ chown -R -h 0

chown: cannot access '': No such file or directory

+ chgrp -R -h 0

chgrp: cannot access '': No such file or directory

+ /usr/bin/sudo -EH -u decidim bundle install

Fetching gem metadata from https://rubygems.org/.......

Fetching gem metadata from https://rubygems.org/.........

Fetching gem metadata from https://rubygems.org/.........

Resolving dependencies...............

Bundler found conflicting requirements for the Ruby version:

 In Gemfile:

  Ruby (~> 2.6.6.0)



  decidim was resolved to 0.24.0.dev, which depends on

   Ruby (>= 2.7)



Ruby (>= 2.7), which is required by gem 'decidim', is not available in the local ruby installation