Revert "bump ruby to 3.0"

This reverts commit 632e2c9f41.

.rubocop.yml

@@ -3,7 +3,7 @@ require:
   - rubocop-rspec
 
 AllCops:
-  TargetRubyVersion: 3.0
+  TargetRubyVersion: 2.7
   # Enable any new cops in new versions by default
   NewCops: enable
   Exclude:

.ruby-version

@@ -1 +1 @@
-3.0.3
+2.7.5

Gemfile

@@ -28,7 +28,7 @@
 
 source 'https://rubygems.org'
 
-ruby '~> 3.0.3'
+ruby '~> 2.7.5'
 
 gem 'actionpack-xml_parser', '~> 2.0.0'
 gem 'activemodel-serializers-xml', '~> 1.0.1'

Gemfile.lock

@@ -1141,7 +1141,7 @@ DEPENDENCIES
   with_advisory_lock (~> 4.6.0)
 
 RUBY VERSION
-   ruby 3.0.3p157
+   ruby 2.7.5p203
 
 BUNDLED WITH
-   2.2.32
+   2.1.4

config/boot.rb

@@ -40,7 +40,7 @@ require 'bundler/setup' # Set up gems listed in the Gemfile.
 
 env = ENV['RAILS_ENV']
 # Disable deprecation warnings early on (before loading gems), which behaves as RUBYOPT="-w0"
-# to disable the Ruby warnings in production.
+# to disable the Ruby 2.7 warnings in production.
 # Set OPENPROJECT_PROD_DEPRECATIONS=true if you want to see them for debugging purposes
 if env == 'production' && ENV['OPENPROJECT_PROD_DEPRECATIONS'] != 'true'
   require 'structured_warnings'

docker/ci/Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:3.0.3-buster
+FROM ruby:2.7.5-buster
 MAINTAINER operations@openproject.com
 
 ENV NODE_VERSION="14.17.0"

docker/dev/backend/Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:3.0.3-buster as develop
+FROM ruby:2.7.5-buster as develop
 MAINTAINER operations@openproject.com
 
 ARG DEV_UID=1000

docker/prod/Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:3.0.3-buster
+FROM ruby:2.7.5-buster
 MAINTAINER operations@openproject.com
 
 # Allow platform-specific additions. Valid values are: on-prem,saas,bahn

docs/development/development-environment-docker/README.md

@@ -191,7 +191,8 @@ rebuild the image. For instance when the Ruby version is updated you may run int
 an error like the following when running `bin/compose setup`:
 
 ```
-Your Ruby version is 2.7.4, but your Gemfile specified ~> 3.0.3
+Creating core_backend_run ... done
+Your Ruby version is 2.7.1, but your Gemfile specified ~> 2.7.5
 ```
 
 This means that the current image is out-dated. You can update it like this:

docs/development/development-environment-osx/README.md

@@ -15,7 +15,7 @@ We'll use [homebrew](https://brew.sh/) to install most of our requirements. Plea
 
 ## Install Ruby
 
-Use [rbenv](https://github.com/rbenv/rbenv) and [ruby-build](https://github.com/rbenv/ruby-build#readme) to install Ruby. We always require the latest ruby versions, and you can check which version is required by [checking the Gemfile](https://github.com/opf/openproject/blob/dev/Gemfile#L31) for the `ruby "~> X.Y"` statement. At the time of writing, this version is "3.0.3"
+Use [rbenv](https://github.com/rbenv/rbenv) and [ruby-build](https://github.com/rbenv/ruby-build#readme) to install Ruby. We always require the latest ruby versions, and you can check which version is required by [checking the Gemfile](https://github.com/opf/openproject/blob/dev/Gemfile#L31) for the `ruby "~> X.Y"` statement. At the time of writing, this version is "2.6"
 
 ### Install rbenv and ruby-build
 
@@ -29,23 +29,23 @@ $ brew install rbenv ruby-build
 $ rbenv init
 ```
 
-### Installing ruby-3.0
+### Installing ruby-2.7
 
-With both installed, we can now install the actual ruby version 3.0. You can check available ruby versions with `rbenv install --list`.
-At the time of this writing, the latest stable version is `3.0.3`, which we also require.
+With both installed, we can now install the actual ruby version 2.7. You can check available ruby versions with `rbenv install --list`.
+At the time of this writing, the latest stable version is `2.7.5`, which we also require.
 
 We suggest you install the version we require in the [Gemfile](https://github.com/opf/openproject/blob/dev/Gemfile). Search for the `ruby '~> X.Y.Z'` line
 and install that version.
 
 ```bash
 # Install the required version as read from the Gemfile
-rbenv install 3.0.3
+rbenv install 2.7.5
 ```
 
 This might take a while depending on whether ruby is built from source. After it is complete, you need to tell rbenv to globally activate this version
 
 ```bash
-rbenv global 3.0.3
+rbenv global 2.7.5
 ```
 
 You also need to install [bundler](https://github.com/bundler/bundler/), the ruby gem bundler.
@@ -116,7 +116,7 @@ You should now have an active ruby and node installation. Verify that it works w
 
 ```bash
 $ ruby --version
-ruby 3.0.3p157 (2021-11-24 revision 3fb7d2cadc) [x86_64-darwin20]
+ruby 2.7.5p203 (2021-07-07 revision a21a3b7d23) [x86_64-linux]
 
 $ bundler --version
 Bundler version 2.1.4

docs/development/development-environment-ubuntu/README.md

@@ -26,7 +26,7 @@ sudo apt-get install git curl build-essential zlib1g-dev libyaml-dev libssl-dev
 
 ## Install Ruby
 
-Use [rbenv](https://github.com/rbenv/rbenv) and [ruby-build](https://github.com/rbenv/ruby-build#readme) to install Ruby. We always require the latest ruby versions, and you can check which version is required by [checking the Gemfile](https://github.com/opf/openproject/blob/dev/Gemfile#L31) for the `ruby "~> X.Y"` statement. At the time of writing, this version is "3.0.3"
+Use [rbenv](https://github.com/rbenv/rbenv) and [ruby-build](https://github.com/rbenv/ruby-build#readme) to install Ruby. We always require the latest ruby versions, and you can check which version is required by [checking the Gemfile](https://github.com/opf/openproject/blob/dev/Gemfile#L31) for the `ruby "~> X.Y"` statement. At the time of writing, this version is "2.7.5"
 
 ### Install rbenv and ruby-build
 
@@ -57,23 +57,23 @@ ruby-build is an addon to rbenv that installs ruby versions
 git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
 ```
 
-### Installing ruby-3.0
+### Installing ruby-2.7
 
-With both installed, we can now install the actual ruby version 3.0. You can check available ruby versions with `rbenv install --list`.
-At the time of this writing, the latest stable version is `3.0.3` which we also require.
+With both installed, we can now install the actual ruby version 2.7. You can check available ruby versions with `rbenv install --list`.
+At the time of this writing, the latest stable version is `2.7.5`, which we also require.
 
 We suggest you install the version we require in the [Gemfile](https://github.com/opf/openproject/blob/dev/Gemfile). Search for the `ruby '~> X.Y.Z'` line
 and install that version.
 
 ```bash
 # Install the required version as read from the Gemfile
-rbenv install 3.0.3
+rbenv install 2.7.5
 ```
 
 This might take a while depending on whether ruby is built from source. After it is complete, you need to tell rbenv to globally activate this version
 
 ```bash
-rbenv global 3.0.3
+rbenv global 2.7.5
 rbenv rehash
 ```
 
@@ -159,11 +159,7 @@ You should now have an active ruby and node installation. Verify that it works w
 
 ```bash
 ruby --version
-<<<<<<< HEAD
 ruby 2.7.5p203 (2021-11-24 revision f69aeb8314) [x86_64-linux]
-=======
-ruby 3.0.3p157 (2021-11-24 revision 3fb7d2cadc) [x86_64-darwin20]
->>>>>>> 003c95615c (bump ruby to 3.0)
 
 bundler --version
 Bundler version 2.2.33

docs/installation-and-operations/installation/manual/README.md

@@ -106,16 +106,16 @@ time to finish.
 [openproject@host] source ~/.profile
 [openproject@host] git clone https://github.com/sstephenson/ruby-build.git ~/.rbenv/plugins/ruby-build
 
-[openproject@host] rbenv install 3.0.3
+[openproject@host] rbenv install 2.7.5
 [openproject@host] rbenv rehash
-[openproject@host] rbenv global 3.0.3
+[openproject@host] rbenv global 2.7.5
 ```
 
 To check our Ruby installation we run `ruby --version`. It should output
 something very similar to:
 
 ```
-ruby 3.0.3p157 (2021-11-24 revision 3fb7d2cadc) [x86_64-darwin20]
+ruby 2.7.5p203 (2021-07-07 revision a21a3b7d23) [x86_64-linux]
 ```
 
 ## Installation of Node