diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 0ac4d3b3b..bee9af5a8 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -70,7 +70,10 @@ jobs:
       - name: Checkout redmine_sidekiq
         uses: actions/checkout@v2
         with:
-          repository: ogom/redmine_sidekiq
+          # TODO Switch back to the original repo, once the "fix-rails-6" PR gets accepted
+          # repository: ogom/redmine_sidekiq
+          repository: dosyfier/redmine_sidekiq
+          ref: fix-rails-6
           path: redmine/plugins/redmine_sidekiq
 
       - name: Checkout gitolite
@@ -93,6 +96,7 @@ jobs:
           libmysqlclient-dev
           libssh2-1
           libssh2-1-dev
+          pkg-config
           subversion
 
       - name: Setup Ruby
@@ -125,6 +129,7 @@ jobs:
         working-directory: redmine
         run: |
           bundle config set --local without 'development'
+          bundle config build.rugged --with-ssh
           bundle install --jobs=4 --retry=3
 
       - name: Run Redmine rake tasks
diff --git a/Gemfile b/Gemfile
index b99da09ca..7f35e18b0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 # Gitolite Admin repository management
-gem 'gitolite-rugged', git: 'https://github.com/jbox-web/gitolite-rugged.git', tag: '1.4.0'
+gem 'gitolite-rugged', git: 'https://github.com/dosyfier/gitolite-rugged.git', branch: 'fix-redmine-5'
 
 # Ruby/Rack Git Smart-HTTP Server Handler
 gem 'gitlab-grack', '~> 2.0.0', git: 'https://github.com/jbox-web/grack.git', require: 'grack', branch: 'fix_gemfile'
diff --git a/app/overrides/repositories/navigation.rb b/app/overrides/repositories/navigation.rb
index ac08134c0..acdcddd8c 100644
--- a/app/overrides/repositories/navigation.rb
+++ b/app/overrides/repositories/navigation.rb
@@ -5,3 +5,8 @@
                      insert_before: 'erb[loud]:contains("label_statistics")',
                      original: '88f120e99075ba3246901c6e970ca671d7166855',
                      text: '<%= call_hook(:view_repositories_navigation, repository: @repository) %>'
+
+module Repositories
+  module Navigation
+  end
+end
diff --git a/app/overrides/repositories/show.rb b/app/overrides/repositories/show.rb
index ab04680fe..6157c285f 100644
--- a/app/overrides/repositories/show.rb
+++ b/app/overrides/repositories/show.rb
@@ -11,3 +11,8 @@
                      insert_before: 'erb[silent]:contains("html_title")',
                      original: '2a0a09659d76066b896016c72527d479c69463ec',
                      partial: 'hooks/show_repositories_sidebar'
+
+module Repositories
+  module Show
+  end
+end
diff --git a/contrib/hooks/post-receive/lib/git_hosting_http_helper.rb b/contrib/hooks/post-receive/lib/git_hosting_http_helper.rb
index 74195023b..2f70de981 100644
--- a/contrib/hooks/post-receive/lib/git_hosting_http_helper.rb
+++ b/contrib/hooks/post-receive/lib/git_hosting_http_helper.rb
@@ -8,7 +8,7 @@
 module GitHosting
   module HttpHelper
     def http_post(url, opts = {}, &block)
-      http, request = build_post_request url, opts
+      http, request = build_post_request url, **opts
       send_http_request http, request, &block
     end
 
diff --git a/init.rb b/init.rb
index 6dd386ae3..44a427ec9 100644
--- a/init.rb
+++ b/init.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+$LOAD_PATH.unshift "#{File.dirname(__FILE__)}/lib"
 
 Redmine::Plugin.register :redmine_git_hosting do
   name        'Redmine Git Hosting Plugin'
diff --git a/lib/hrack/lib/hrack/bundle.rb b/lib/hrack/bundle.rb
similarity index 92%
rename from lib/hrack/lib/hrack/bundle.rb
rename to lib/hrack/bundle.rb
index fa5ab570b..4534ef9ad 100644
--- a/lib/hrack/lib/hrack/bundle.rb
+++ b/lib/hrack/bundle.rb
@@ -2,7 +2,6 @@
 
 require 'rack/builder'
 require 'rack/parser'
-require 'hrack/server'
 
 module Hrack
   module Bundle
diff --git a/lib/hrack/init.rb b/lib/hrack/init.rb
deleted file mode 100644
index ae5663c2d..000000000
--- a/lib/hrack/init.rb
+++ /dev/null
@@ -1,4 +0,0 @@
-# frozen_string_literal: true
-
-$LOAD_PATH.push File.expand_path('lib', __dir__)
-require 'hrack'
diff --git a/lib/hrack/lib/hrack.rb b/lib/hrack/lib/hrack.rb
deleted file mode 100644
index 231f9c359..000000000
--- a/lib/hrack/lib/hrack.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-# frozen_string_literal: true
-
-module Hrack
-  require 'hrack/bundle'
-end
diff --git a/lib/hrack/lib/hrack/server.rb b/lib/hrack/server.rb
similarity index 100%
rename from lib/hrack/lib/hrack/server.rb
rename to lib/hrack/server.rb
diff --git a/lib/hrack/lib/hrack/version.rb b/lib/hrack/version.rb
similarity index 74%
rename from lib/hrack/lib/hrack/version.rb
rename to lib/hrack/version.rb
index 52c448969..acc8bd606 100644
--- a/lib/hrack/lib/hrack/version.rb
+++ b/lib/hrack/version.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
 module Hrack
+  module Version
+  end
   VERSION = '1.0.0'
 end
diff --git a/lib/load_gitolite_hooks.rb b/lib/load_gitolite_hooks.rb
index 9ad3e52d9..7008c9add 100644
--- a/lib/load_gitolite_hooks.rb
+++ b/lib/load_gitolite_hooks.rb
@@ -72,3 +72,6 @@
 ].each do |file|
   require_dependency file if File.exist? file
 end
+
+module LoadGitoliteHooks
+end
diff --git a/lib/redmine/scm/adapters/xitolite_adapter.rb b/lib/redmine/scm/adapters/xitolite_adapter.rb
index e5c70d319..eb8f39783 100644
--- a/lib/redmine/scm/adapters/xitolite_adapter.rb
+++ b/lib/redmine/scm/adapters/xitolite_adapter.rb
@@ -187,7 +187,7 @@ def lastrev(path, rev)
           nil
         end
 
-        def revisions(path, identifier_from, identifier_to, **options)
+        def revisions(path, identifier_from, identifier_to, options={})
           revs = Revisions.new
           cmd_args = %w[log --no-color --encoding=UTF-8 --raw --date=iso --pretty=fuller --parents --stdin]
           cmd_args << '--no-renames' if self.class.client_version_above? [2, 9]
diff --git a/lib/redmine_git_hosting.rb b/lib/redmine_git_hosting.rb
index 2fa95ed14..29c566b4e 100644
--- a/lib/redmine_git_hosting.rb
+++ b/lib/redmine_git_hosting.rb
@@ -65,5 +65,5 @@ def additionals_help_items
   # Redmine SCM adapter
   require_dependency 'redmine/scm/adapters/xitolite_adapter'
 
-  require 'hrack/init'
+  require 'hrack/bundle'
 end
diff --git a/lib/redmine_git_hosting/cache/abstract_cache.rb b/lib/redmine_git_hosting/cache/abstract_cache.rb
index c68e0b83a..171a60d15 100644
--- a/lib/redmine_git_hosting/cache/abstract_cache.rb
+++ b/lib/redmine_git_hosting/cache/abstract_cache.rb
@@ -56,7 +56,7 @@ def time_limit
         def valid_cache_entry?(cached_entry_date)
           return true if max_cache_time.to_i.negative? # No expiration needed
 
-          current_time = ActiveRecord::Base.default_timezone == :utc ? Time.now.utc : Timezone.now
+          current_time = ActiveRecord::Base.default_timezone == :utc ? Time.now.utc : Time.zone.now
           expired = current_time.to_i - cached_entry_date.to_i > max_cache_time
           !expired
         end
diff --git a/lib/redmine_git_hosting/console_logger.rb b/lib/redmine_git_hosting/console_logger.rb
index 9589a184c..b5d8881ff 100644
--- a/lib/redmine_git_hosting/console_logger.rb
+++ b/lib/redmine_git_hosting/console_logger.rb
@@ -6,7 +6,7 @@ module ConsoleLogger
 
     def title(message)
       info "\n * #{message}:"
-      yield if block
+      yield if block_given?
       info " Done!\n\n"
     end
 
diff --git a/lib/redmine_git_hosting/gitolite_handlers/repositories/add_repository.rb b/lib/redmine_git_hosting/gitolite_handlers/repositories/add_repository.rb
index b0fa113ea..20e05a329 100644
--- a/lib/redmine_git_hosting/gitolite_handlers/repositories/add_repository.rb
+++ b/lib/redmine_git_hosting/gitolite_handlers/repositories/add_repository.rb
@@ -30,10 +30,10 @@ def gitolite_repo_path
 
         attr_reader :force
 
-        def initialize(*args)
-          super
-          @force     = options.delete(:force) { false }
-          @old_perms = options.delete(:old_perms) { {} }
+        def initialize(gitolite_config, repository, context, **options)
+          super(gitolite_config, repository, context, **options)
+          @force     = @options.delete(:force) { false }
+          @old_perms = @options.delete(:old_perms) { {} }
         end
       end
     end
diff --git a/lib/redmine_git_hosting/gitolite_wrappers/base.rb b/lib/redmine_git_hosting/gitolite_wrappers/base.rb
index c95c30db5..705034842 100644
--- a/lib/redmine_git_hosting/gitolite_wrappers/base.rb
+++ b/lib/redmine_git_hosting/gitolite_wrappers/base.rb
@@ -49,19 +49,19 @@ def gitolite_admin_repo_commit(message = '')
       end
 
       def create_gitolite_repository(repository)
-        GitoliteHandlers::Repositories::AddRepository.call gitolite_config, repository, context, options
+        GitoliteHandlers::Repositories::AddRepository.call gitolite_config, repository, context, **options
       end
 
       def update_gitolite_repository(repository)
-        GitoliteHandlers::Repositories::UpdateRepository.call gitolite_config, repository, context, options
+        GitoliteHandlers::Repositories::UpdateRepository.call gitolite_config, repository, context, **options
       end
 
       def delete_gitolite_repository(repository)
-        GitoliteHandlers::Repositories::DeleteRepository.call gitolite_config, repository, context, options
+        GitoliteHandlers::Repositories::DeleteRepository.call gitolite_config, repository, context, **options
       end
 
       def move_gitolite_repository(repository)
-        GitoliteHandlers::Repositories::MoveRepository.call gitolite_config, repository, context, options
+        GitoliteHandlers::Repositories::MoveRepository.call gitolite_config, repository, context, **options
       end
 
       def create_gitolite_key(key)
diff --git a/lib/redmine_git_hosting/gitolite_wrappers/repositories/add_repository.rb b/lib/redmine_git_hosting/gitolite_wrappers/repositories/add_repository.rb
index 761ecc9c4..4529b0ccf 100644
--- a/lib/redmine_git_hosting/gitolite_wrappers/repositories/add_repository.rb
+++ b/lib/redmine_git_hosting/gitolite_wrappers/repositories/add_repository.rb
@@ -35,7 +35,7 @@ def create_repository
           logger.info 'Execute Gitolite Plugins'
 
           # Create README file or initialize GitAnnex
-          RedmineGitHosting::Plugins.execute :post_create, repository, options.merge(recovered: @recovered)
+          RedmineGitHosting::Plugins.execute :post_create, repository, **options.merge(recovered: @recovered)
 
           # Fetch changeset
           repository.fetch_changesets
diff --git a/lib/redmine_git_hosting/gitolite_wrappers/repositories/update_repository.rb b/lib/redmine_git_hosting/gitolite_wrappers/repositories/update_repository.rb
index e105932c1..bed853c4b 100644
--- a/lib/redmine_git_hosting/gitolite_wrappers/repositories/update_repository.rb
+++ b/lib/redmine_git_hosting/gitolite_wrappers/repositories/update_repository.rb
@@ -26,7 +26,7 @@ def update_repository
           logger.info 'Execute Gitolite Plugins'
 
           # Delete Git Config Keys
-          RedmineGitHosting::Plugins.execute :post_update, repository, options
+          RedmineGitHosting::Plugins.execute :post_update, repository, **options
 
           # Fetch changeset
           repository.fetch_changesets
diff --git a/lib/redmine_git_hosting/hooks.rb b/lib/redmine_git_hosting/hooks.rb
index a6eb0fad1..75ed5665c 100644
--- a/lib/redmine_git_hosting/hooks.rb
+++ b/lib/redmine_git_hosting/hooks.rb
@@ -3,70 +3,72 @@
 require 'github/markup'
 
 module RedmineGitHosting
-  class GitHostingHookListener < Redmine::Hook::ViewListener
-    render_on :view_repository_edit_top, partial: 'repositories/edit_top'
-    render_on :view_repositories_show_contextual, partial: 'repositories/show_top'
-    render_on :view_repository_edit_bottom, partial: 'repositories/edit_bottom'
-    render_on :view_repositories_show_sidebar, partial: 'repositories/git_hosting_sidebar'
-    render_on :view_repositories_navigation, partial: 'repositories/git_hosting_navigation'
-    render_on :view_layouts_base_html_head, partial: 'common/git_hosting_html_head'
-
-    def view_my_account_contextual(context)
-      user = context[:user]
-      link_to(l(:label_my_public_keys), public_keys_path, class: 'icon icon-passwd') if user.allowed_to_create_ssh_keys?
-    end
+  module Hooks
+    class GitHostingHookListener < Redmine::Hook::ViewListener
+      render_on :view_repository_edit_top, partial: 'repositories/edit_top'
+      render_on :view_repositories_show_contextual, partial: 'repositories/show_top'
+      render_on :view_repository_edit_bottom, partial: 'repositories/edit_bottom'
+      render_on :view_repositories_show_sidebar, partial: 'repositories/git_hosting_sidebar'
+      render_on :view_repositories_navigation, partial: 'repositories/git_hosting_navigation'
+      render_on :view_layouts_base_html_head, partial: 'common/git_hosting_html_head'
+
+      def view_my_account_contextual(context)
+        user = context[:user]
+        link_to(l(:label_my_public_keys), public_keys_path, class: 'icon icon-passwd') if user.allowed_to_create_ssh_keys?
+      end
 
-    def self.default_url_options
-      { script_name: Redmine::Utils.relative_url_root }
-    end
+      def self.default_url_options
+        { script_name: Redmine::Utils.relative_url_root }
+      end
 
-    def view_repositories_show_bottom(context)
-      path        = get_path context
-      rev         = get_rev context
-      repository  = context[:repository]
-      readme_file = find_readme_file repository, path, rev
+      def view_repositories_show_bottom(context)
+        path        = get_path context
+        rev         = get_rev context
+        repository  = context[:repository]
+        readme_file = find_readme_file repository, path, rev
 
-      return '' if readme_file.nil?
+        return '' if readme_file.nil?
 
-      content = get_formatted_text repository, readme_file, rev
+        content = get_formatted_text repository, readme_file, rev
 
-      context[:controller].send :render_to_string, partial: 'repositories/readme', locals: { html: content }
-    end
-
-    private
+        context[:controller].send :render_to_string, partial: 'repositories/readme', locals: { html: content }
+      end
 
-    def get_path(context)
-      context[:request].params['path'] || ''
-    end
+      private
 
-    def get_rev(context)
-      rev = context[:request].params['rev']
-      rev.presence
-    end
+      def get_path(context)
+        context[:request].params['path'] || ''
+      end
 
-    def find_readme_file(repository, path, rev)
-      (repository.entries(path, rev) || []).find { |f| f.name =~ /README((\.).*)?/i }
-    end
+      def get_rev(context)
+        rev = context[:request].params['rev']
+        rev.presence
+      end
 
-    def get_formatted_text(repository, file, rev)
-      raw_readme_text = Redmine::CodesetUtil.to_utf8_by_setting repository.cat(file.path, rev)
+      def find_readme_file(repository, path, rev)
+        (repository.entries(path, rev) || []).find { |f| f.name =~ /README((\.).*)?/i }
+      end
 
-      if redmine_file? file
-        formatter_name = Redmine::WikiFormatting.format_names.find { |name| name =~ /markdown/i }
-        Redmine::WikiFormatting.formatter_for(formatter_name).new(raw_readme_text).to_html
-      elsif github_file? file
-        RedmineGitHosting::MarkdownRenderer.to_html raw_readme_text
-      else
-        GitHub::Markup.render(file.path, raw_readme_text).gsub("\n", '<br/>')
+      def get_formatted_text(repository, file, rev)
+        raw_readme_text = Redmine::CodesetUtil.to_utf8_by_setting repository.cat(file.path, rev)
+
+        if redmine_file? file
+          formatter_name = Redmine::WikiFormatting.format_names.find { |name| name =~ /markdown/i }
+          Redmine::WikiFormatting.formatter_for(formatter_name).new(raw_readme_text).to_html
+        elsif github_file? file
+          RedmineGitHosting::MarkdownRenderer.to_html raw_readme_text
+        else
+          GitHub::Markup.render(file.path, raw_readme_text).gsub("\n", '<br/>')
+        end
       end
-    end
 
-    def redmine_file?(file)
-      %w[.txt].include? File.extname(file.path)
-    end
+      def redmine_file?(file)
+        %w[.txt].include? File.extname(file.path)
+      end
 
-    def github_file?(file)
-      %w[.markdown .mdown .mkdn .md].include? File.extname(file.path)
+      def github_file?(file)
+        %w[.markdown .mdown .mkdn .md].include? File.extname(file.path)
+      end
     end
   end
 end
diff --git a/lib/redmine_git_hosting/journal_logger.rb b/lib/redmine_git_hosting/journal_logger.rb
index b1ed8f63a..5bcaa8488 100644
--- a/lib/redmine_git_hosting/journal_logger.rb
+++ b/lib/redmine_git_hosting/journal_logger.rb
@@ -36,5 +36,8 @@ def msg2str(msg)
         end
       end
     end
+  else
+    module JournalLogger
+    end
   end
 end
diff --git a/lib/redmine_git_hosting/plugins/extenders/branch_updater.rb b/lib/redmine_git_hosting/plugins/extenders/branch_updater.rb
index f3440e9ba..421748981 100644
--- a/lib/redmine_git_hosting/plugins/extenders/branch_updater.rb
+++ b/lib/redmine_git_hosting/plugins/extenders/branch_updater.rb
@@ -4,8 +4,8 @@ module RedmineGitHosting::Plugins::Extenders
   class BranchUpdater < BaseExtender
     attr_reader :update_default_branch
 
-    def initialize(*args)
-      super
+    def initialize(repository, **options)
+      super(repository, **options)
       @update_default_branch = options.delete(:update_default_branch) { false }
     end
 
diff --git a/lib/redmine_git_hosting/plugins/extenders/config_key_deletor.rb b/lib/redmine_git_hosting/plugins/extenders/config_key_deletor.rb
index 7acd7e596..9dd60321a 100644
--- a/lib/redmine_git_hosting/plugins/extenders/config_key_deletor.rb
+++ b/lib/redmine_git_hosting/plugins/extenders/config_key_deletor.rb
@@ -4,8 +4,8 @@ module RedmineGitHosting::Plugins::Extenders
   class ConfigKeyDeletor < BaseExtender
     attr_reader :delete_git_config_key
 
-    def initialize(*args)
-      super
+    def initialize(repository, **options)
+      super(repository, **options)
       @delete_git_config_key = options.delete(:delete_git_config_key) { '' }
     end
 
diff --git a/lib/redmine_git_hosting/plugins/extenders/git_annex_creator.rb b/lib/redmine_git_hosting/plugins/extenders/git_annex_creator.rb
index 14b22ec57..f49d8b184 100644
--- a/lib/redmine_git_hosting/plugins/extenders/git_annex_creator.rb
+++ b/lib/redmine_git_hosting/plugins/extenders/git_annex_creator.rb
@@ -4,8 +4,8 @@ module RedmineGitHosting::Plugins::Extenders
   class GitAnnexCreator < BaseExtender
     attr_reader :enable_git_annex
 
-    def initialize(*args)
-      super
+    def initialize(repository, **options)
+      super(repository, **options)
       @enable_git_annex = options.delete(:enable_git_annex) { false }
     end
 
diff --git a/lib/redmine_git_hosting/plugins/extenders/readme_creator.rb b/lib/redmine_git_hosting/plugins/extenders/readme_creator.rb
index 428bb3d43..fc37e9903 100644
--- a/lib/redmine_git_hosting/plugins/extenders/readme_creator.rb
+++ b/lib/redmine_git_hosting/plugins/extenders/readme_creator.rb
@@ -6,8 +6,8 @@ module RedmineGitHosting::Plugins::Extenders
   class ReadmeCreator < BaseExtender
     attr_reader :create_readme_file
 
-    def initialize(*args)
-      super
+    def initialize(repository, **options)
+      super(repository, **options)
       @create_readme_file = options.delete(:create_readme_file) { false }
     end