Ruby 3: `gem install docker-sync` installs version 0.0.11

[mystix]

Attempting to install the docker-sync gem in a Ruby 3.x environment results in the v0.0.11 version of docker-sync being installed.

Attempting to install higher versions of the docker-sync gem results in the following error:

❯ gem install docker-sync -v 0.6.0
ERROR:  While executing gem ... (NoMethodError)
    undefined method `request' for nil:NilClass

To investigate, I cloned the docker-sync git repository and attempted to run bundle update within:

❯ bundle update
Fetching gem metadata from https://rubygems.org/.......
Resolving dependencies...
Bundler found conflicting requirements for the Ruby version:
  In Gemfile:
    Ruby

    docker-sync was resolved to 0.6.0, which depends on
      docker-compose (~> 1.1, >= 1.1.7) was resolved to 1.1.12, which depends on
        Ruby (~> 2.0)

    docker-sync was resolved to 0.6.0, which depends on
      Ruby (>= 2.4)

    rspec was resolved to 3.10.0, which depends on
      rspec-core (~> 3.10.0) was resolved to 3.10.1, which depends on
        Ruby (>= 1.8.7)

    docker-sync was resolved to 0.6.0, which depends on
      thor (~> 1.0, >= 1.0.0) was resolved to 1.1.0, which depends on
        Ruby (>= 2.0.0)

Bundler could not find compatible versions for gem "docker-sync":
  In Gemfile:
    docker-sync

which reveals the underlying issue lies with the docker-compose gem, which depends specifically on Ruby 2.x.

Going further down the rabbit hole, docker-compose depends on backtick, which again depends on Ruby 2.x.

[EugenMayer]

I will not work on getting docket-sync ruby 3.0 compatible myself. So if you want to love this issue, you will have to invest your time (heavily I guess).

[fatso83]

Ooh, this is probably why nothing works. Tried following the docs as closely as I could, but stumbled upon all kinds of ancient issues (like #271 not being implemented). I was indeed running 0.0.11 - quite a far stretch from the 0.7 version that is current 😃

While I support not spending lots of time supporting Ruby 3, I would make a note of this somewhere in the docs and the README, as this is the default shipped with new macOS 12 (which I am running). Otherwise this issue will become a lot noisier in time! Maybe even just ship a dummy gem that target Ruby 3 that prints out "This project requires Ruby 2" or something.

[donnykurnia]

In macOS, using homebrew, install ruby 2.7:

brew install ruby@2.7

[EugenMayer]

This effort can be combined #788 and #787

[pnbecker]

Also see #766

[EugenMayer]

Seems like we move near ruby 3 with #795 and thus can replace the old 0.0.11 variant with that

[guilhermeteodoro]

Hey guys, just passing by to thank you all for this fix <3 you're awesome!