diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 73182c797a..2bbbf857c0 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -15,12 +15,83 @@ jobs:
 
     - name: Set up Homebrew
       run: |
-        HOMEBREW_REPOSITORY="$(brew --repo)"
-        mv "$HOMEBREW_REPOSITORY/Library/Taps" "$PWD/Library"
-        sudo rm -rf "$HOMEBREW_REPOSITORY"
-        sudo ln -s "$PWD" "$HOMEBREW_REPOSITORY"
-        brew update-reset Library/Taps/homebrew/homebrew-core
-      if: matrix.os == 'macOS-latest'
+        if [ "$RUNNER_OS" = "Linux" ]; then
+          HOMEBREW_REPOSITORY=/home/linuxbrew/.linuxbrew
+          sudo mkdir -p /home/linuxbrew
+          sudo ln -s "$PWD" "$HOMEBREW_REPOSITORY"
+          sudo chown -R "$USER" /home/linuxbrew
+        else
+          HOMEBREW_REPOSITORY="$(brew --repo)"
+          mv "$HOMEBREW_REPOSITORY/Library/Taps" "$PWD/Library"
+          sudo rm -rf "$HOMEBREW_REPOSITORY"
+          sudo ln -s "$PWD" "$HOMEBREW_REPOSITORY"
+          brew update-reset Library/Taps/homebrew/homebrew-core
+
+          # Install taps needed for 'brew tests'
+          brew tap homebrew/cask
+          brew tap homebrew/bundle
+          brew tap homebrew/services
+        fi
+
+    - name: Install Bundler RubyGems
+      run: |
+        export PATH="/home/linuxbrew/.linuxbrew/bin:/usr/local/bin:/usr/bin:/bin"
+        brew install-bundler-gems
+
+        # Check for uncommitted gems
+        git -C $(brew --repo) diff --stat --exit-code Library/Homebrew/vendor/bundle/ruby
+
+        if [ "$RUNNER_OS" = "Linux" ]; then
+          # Fix permissions for 'brew tests'
+          sudo chmod -R g-w,o-w /home/linuxbrew /home/runner /opt
+        fi
+
+    - name: Run brew tests
+      run: |
+        # brew tests doesn't like world writable directories
+        umask 022
+
+        # set variables for coverage reporting
+        export HOMEBREW_CI_BUILD_NUMBER="$GITHUB_REF"
+        export HOMEBREW_CI_BRANCH="$HEAD_GITHUB_REF"
+        export HOMEBREW_GITHUB_REPOSITORY="$GITHUB_REPOSITORY"
+
+        export PATH="/home/linuxbrew/.linuxbrew/bin:/usr/local/bin:/usr/bin:/bin"
+        brew tests --no-compat --online
+        brew tests --generic --online
+        brew tests --online --coverage
+      env:
+        HOMEBREW_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+        # set variables for coverage reporting
+        HOMEBREW_GITHUB_ACTIONS: 1
+        HOMEBREW_CI_NAME: github-actions
+        HOMEBREW_COVERALLS_REPO_TOKEN: 3F6U6ZqctoNJwKyREremsqMgpU3qYgxFk
+
+        # These cannot be queried at the macOS level on GitHub Actions.
+        HOMEBREW_LANGUAGES: en-GB
+
+    - name: Run brew style
+      run: |
+        export PATH="/home/linuxbrew/.linuxbrew/bin:/usr/local/bin:/usr/bin:/bin"
+        brew style
+
+    - name: Run brew man
+      run: |
+        export PATH="/home/linuxbrew/.linuxbrew/bin:/usr/local/bin:/usr/bin:/bin"
+        brew man --fail-if-changed
+
+    - name: Run brew update-tests
+      run: |
+        export PATH="/home/linuxbrew/.linuxbrew/bin:/usr/local/bin:/usr/bin:/bin"
+        brew update-test
+        brew update-test --to-tag
+        brew update-test --commit=HEAD
+
+    - name: Run brew readall
+      run: |
+        export PATH="/home/linuxbrew/.linuxbrew/bin:/usr/local/bin:/usr/bin:/bin"
+        brew readall --aliases
 
     - name: Build Docker image
       run: |
@@ -35,6 +106,3 @@ jobs:
         else
           brew test-bot
         fi
-      env:
-        HOMEBREW_COVERALLS_REPO_TOKEN: 3F6U6ZqctoNJwKyREremsqMgpU3qYgxFk
-        HOMEBREW_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/Dockerfile.yml b/Dockerfile.yml
index 3c255e2ba8..ac02ce9147 100644
--- a/Dockerfile.yml
+++ b/Dockerfile.yml
@@ -15,21 +15,3 @@ services:
         /home/linuxbrew/.linuxbrew/bin/brew test-bot
         status=$$?
         exit $$status
-    environment:
-      # GitHub Actions
-      - GITHUB_ACTIONS
-      - GITHUB_BASE_REF
-      - GITHUB_EVENT_NAME
-      - GITHUB_REF
-      - GITHUB_REPOSITORY
-      - GITHUB_SHA
-      - HEAD_GITHUB_REF
-      # Azure Pipelines
-      - BUILD_REASON
-      - BUILD_REPOSITORY_URI
-      - BUILD_SOURCEVERSION
-      - SYSTEM_PULLREQUEST_PULLREQUESTNUMBER
-      - SYSTEM_PULLREQUEST_TARGETBRANCH
-      - TF_BUILD
-      # GitHub API
-      - HOMEBREW_GITHUB_API_TOKEN
diff --git a/Library/Homebrew/dev-cmd/install-bundler-gems.rb b/Library/Homebrew/dev-cmd/install-bundler-gems.rb
new file mode 100644
index 0000000000..421b942074
--- /dev/null
+++ b/Library/Homebrew/dev-cmd/install-bundler-gems.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require "formula"
+require "cli/parser"
+
+module Homebrew
+  module_function
+
+  def install_bundler_gems_args
+    Homebrew::CLI::Parser.new do
+      usage_banner <<~EOS
+        `install-bundler-gems`
+
+        Install Homebrew's Bundler gems.
+      EOS
+      switch :debug
+    end
+  end
+
+  def install_bundler_gems
+    install_bundler_gems_args.parse
+
+    Homebrew.install_bundler_gems!
+  end
+end
diff --git a/Library/Homebrew/test/spec_helper.rb b/Library/Homebrew/test/spec_helper.rb
index d04b8b7208..179f6a5967 100644
--- a/Library/Homebrew/test/spec_helper.rb
+++ b/Library/Homebrew/test/spec_helper.rb
@@ -4,7 +4,7 @@ if ENV["HOMEBREW_TESTS_COVERAGE"]
   require "simplecov"
 
   formatters = [SimpleCov::Formatter::HTMLFormatter]
-  if ENV["HOMEBREW_COVERALLS_REPO_TOKEN"]
+  if ENV["HOMEBREW_COVERALLS_REPO_TOKEN"] && RUBY_PLATFORM[/darwin/]
     require "coveralls"
 
     Coveralls::Output.no_color if !ENV["HOMEBREW_COLOR"] && (ENV["HOMEBREW_NO_COLOR"] || !$stdout.tty?)
@@ -19,12 +19,15 @@ if ENV["HOMEBREW_TESTS_COVERAGE"]
     end
 
     ENV["CI_NAME"] = ENV["HOMEBREW_CI_NAME"]
-    ENV["CI_JOB_ID"] = ENV["TEST_ENV_NUMBER"] || "1"
-    ENV["CI_BUILD_NUMBER"] = ENV["HOMEBREW_CI_BUILD_NUMBER"]
-    ENV["CI_BUILD_URL"] = ENV["HOMEBREW_CI_BUILD_URL"]
-    ENV["CI_BRANCH"] = ENV["HOMEBREW_CI_BRANCH"]
-    ENV["CI_PULL_REQUEST"] = ENV["HOMEBREW_CI_PULL_REQUEST"]
     ENV["COVERALLS_REPO_TOKEN"] = ENV["HOMEBREW_COVERALLS_REPO_TOKEN"]
+
+    ENV["CI_BUILD_NUMBER"] = ENV["HOMEBREW_CI_BUILD_NUMBER"]
+    ENV["CI_BRANCH"] = ENV["HOMEBREW_CI_BRANCH"]
+    %r{refs/pull/(?<pr>\d+)/merge} =~ ENV["HOMEBREW_CI_BUILD_NUMBER"]
+    ENV["CI_PULL_REQUEST"] = pr
+    ENV["CI_BUILD_URL"] = "https://github.com/#{ENV["HOMEBREW_GITHUB_REPOSITORY"]}/pull/#{pr}/checks"
+
+    ENV["CI_JOB_ID"] = ENV["TEST_ENV_NUMBER"] || "1"
   end
 
   SimpleCov.formatters = SimpleCov::Formatter::MultiFormatter.new(formatters)
diff --git a/docs/Manpage.md b/docs/Manpage.md
index 3079d37625..49aa47a6b6 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -840,6 +840,10 @@ formula from a tap that is not `homebrew/core` use its fully-qualified form of
 
 Display the path where *`formula`* is located.
 
+### `install-bundler-gems`
+
+Install Homebrew's Bundler gems.
+
 ### `irb` [*`options`*]
 
 Enter the interactive Homebrew Ruby shell.
diff --git a/manpages/brew.1 b/manpages/brew.1
index 2da8243fbe..0a6816a544 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -1068,6 +1068,9 @@ Extract the specified \fIversion\fR of \fIformula\fR instead of the most recent\
 .SS "\fBformula\fR \fIformula\fR"
 Display the path where \fIformula\fR is located\.
 .
+.SS "\fBinstall\-bundler\-gems\fR"
+Install Homebrew\'s Bundler gems\.
+.
 .SS "\fBirb\fR [\fIoptions\fR]"
 Enter the interactive Homebrew Ruby shell\.
 .