tests: test on Ubuntu 18.04.

.devcontainer/on-create-command.sh

@@ -1,23 +1,15 @@
 #!/bin/bash
 set -e
 
-# dump information variables for debugging
-echo "==> env"
-env | grep -v TOKEN
-echo
-echo "==> /etc/os-release"
-cat /etc/os-release || true
-echo
-echo "==> /etc/lsb-release"
-cat /etc/lsb-release || true
-echo
-echo "==> /etc/issue"
-cat /etc/issue || true
-echo
-
 # fix permissions so Homebrew and Bundler don't complain
 sudo chmod -R g-w,o-w /home/linuxbrew
 
+# everything below is too slow to do unless prebuilding so skip it
+if [ -z "$CODESPACES_PREBUILD_TOKEN" ]
+then
+  exit 0
+fi
+
 # install Homebrew's development gems
 brew install-bundler-gems --groups=sorbet
 

.github/workflows/tests.yml

@@ -12,6 +12,7 @@ permissions:
 env:
   HOMEBREW_DEVELOPER: 1
   HOMEBREW_NO_AUTO_UPDATE: 1
+  HOMEBREW_NO_ENV_HINTS: 1
 
 concurrency:
   group: "${{ github.ref }}"
@@ -235,10 +236,9 @@ jobs:
           - name: tests (Ubuntu 22.04)
             test-flags: --online --coverage
             runs-on: ubuntu-22.04
-          # Enable later once this can be fixed.
-          # - name: tests (Ubuntu 18.04)
-          #   test-flags: --online --coverage
-          #   runs-on: ubuntu-18.04
+          - name: tests (Ubuntu 18.04)
+            test-flags: --online --coverage
+            runs-on: ubuntu-18.04
     steps:
       - name: Set up Homebrew
         id: set-up-homebrew

Library/Homebrew/dev-cmd/tests.rb

@@ -93,55 +93,7 @@ def tests
     require "byebug" if args.byebug?
 
     HOMEBREW_LIBRARY_PATH.cd do
-      # Cleanup any unwanted user configuration.
-      allowed_test_env = %w[
-        HOMEBREW_GITHUB_API_TOKEN
-        HOMEBREW_CACHE
-        HOMEBREW_LOGS
-        HOMEBREW_TEMP
-        HOMEBREW_USE_RUBY_FROM_PATH
-      ]
-      Homebrew::EnvConfig::ENVS.keys.map(&:to_s).each do |env|
-        next if allowed_test_env.include?(env)
-
-        ENV.delete(env)
-      end
-
-      # Codespaces /tmp is mounted 755 which makes Ruby warn constantly.
-      if (ENV["HOMEBREW_CODESPACES"] == "true") && (HOMEBREW_TEMP.to_s == "/tmp")
-        homebrew_prefix_tmp = "#{HOMEBREW_PREFIX}/tmp"
-        ENV["HOMEBREW_TEMP"] = homebrew_prefix_tmp
-        FileUtils.mkdir_p homebrew_prefix_tmp
-        system "chmod", "-R", "g-w,o-w", "/tmp"
-      end
-
-      ENV["HOMEBREW_NO_ANALYTICS_THIS_RUN"] = "1"
-      ENV["HOMEBREW_NO_COMPAT"] = "1" if args.no_compat?
-      ENV["HOMEBREW_TEST_GENERIC_OS"] = "1" if args.generic?
-      ENV["HOMEBREW_TEST_ONLINE"] = "1" if args.online?
-      ENV["HOMEBREW_SORBET_RUNTIME"] = "1"
-
-      ENV["USER"] ||= system_command!("id", args: ["-nu"]).stdout.chomp
-
-      # Avoid local configuration messing with tests, e.g. git being configured
-      # to use GPG to sign by default
-      ENV["HOME"] = "#{HOMEBREW_LIBRARY_PATH}/test"
-
-      # Print verbose output when requesting debug or verbose output.
-      ENV["HOMEBREW_VERBOSE_TESTS"] = "1" if args.debug? || args.verbose?
-
-      if args.coverage?
-        ENV["HOMEBREW_TESTS_COVERAGE"] = "1"
-        FileUtils.rm_f "test/coverage/.resultset.json"
-      end
-
-      # Override author/committer as global settings might be invalid and thus
-      # will cause silent failure during the setup of dummy Git repositories.
-      %w[AUTHOR COMMITTER].each do |role|
-        ENV["GIT_#{role}_NAME"] = "brew tests"
-        ENV["GIT_#{role}_EMAIL"] = "brew-tests@localhost"
-        ENV["GIT_#{role}_DATE"]  = "Sun Jan 22 19:59:13 2017 +0000"
-      end
+      setup_environment!(args)
 
       parallel = true
 
@@ -237,4 +189,59 @@ def tests
       Homebrew.failed = true
     end
   end
+
+  def setup_environment!(args)
+    # Cleanup any unwanted user configuration.
+    allowed_test_env = %w[
+      HOMEBREW_GITHUB_API_TOKEN
+      HOMEBREW_CACHE
+      HOMEBREW_LOGS
+      HOMEBREW_TEMP
+      HOMEBREW_USE_RUBY_FROM_PATH
+    ]
+    Homebrew::EnvConfig::ENVS.keys.map(&:to_s).each do |env|
+      next if allowed_test_env.include?(env)
+
+      ENV.delete(env)
+    end
+
+    # Codespaces HOMEBREW_PREFIX and /tmp are mounted 755 which makes Ruby warn constantly.
+    if (ENV["HOMEBREW_CODESPACES"] == "true") && (HOMEBREW_TEMP.to_s == "/tmp")
+      # Need to keep this fairly short to avoid socket paths being too long in tests.
+      homebrew_prefix_tmp = "/home/linuxbrew/tmp"
+      ENV["HOMEBREW_TEMP"] = homebrew_prefix_tmp
+      FileUtils.mkdir_p homebrew_prefix_tmp
+      system "chmod", "-R", "g-w,o-w", HOMEBREW_PREFIX, homebrew_prefix_tmp
+    end
+
+    ENV["HOMEBREW_TESTS"] = "1"
+    ENV["HOMEBREW_NO_AUTO_UPDATE"] = "1"
+    ENV["HOMEBREW_NO_ANALYTICS_THIS_RUN"] = "1"
+    ENV["HOMEBREW_NO_COMPAT"] = "1" if args.no_compat?
+    ENV["HOMEBREW_TEST_GENERIC_OS"] = "1" if args.generic?
+    ENV["HOMEBREW_TEST_ONLINE"] = "1" if args.online?
+    ENV["HOMEBREW_SORBET_RUNTIME"] = "1"
+
+    ENV["USER"] ||= system_command!("id", args: ["-nu"]).stdout.chomp
+
+    # Avoid local configuration messing with tests, e.g. git being configured
+    # to use GPG to sign by default
+    ENV["HOME"] = "#{HOMEBREW_LIBRARY_PATH}/test"
+
+    # Print verbose output when requesting debug or verbose output.
+    ENV["HOMEBREW_VERBOSE_TESTS"] = "1" if args.debug? || args.verbose?
+
+    if args.coverage?
+      ENV["HOMEBREW_TESTS_COVERAGE"] = "1"
+      FileUtils.rm_f "test/coverage/.resultset.json"
+    end
+
+    # Override author/committer as global settings might be invalid and thus
+    # will cause silent failure during the setup of dummy Git repositories.
+    %w[AUTHOR COMMITTER].each do |role|
+      ENV["GIT_#{role}_NAME"] = "brew tests"
+      ENV["GIT_#{role}_EMAIL"] = "brew-tests@localhost"
+      ENV["GIT_#{role}_DATE"]  = "Sun Jan 22 19:59:13 2017 +0000"
+    end
+  end
 end

Library/Homebrew/development_tools.rb

@@ -99,12 +99,17 @@ def clear_version_cache
     end
 
     sig { returns(T::Boolean) }
-    def build_system_too_old?
+    def needs_build_formulae?
+      needs_libc_formula? || needs_compiler_formula?
+    end
+
+    sig { returns(T::Boolean) }
+    def needs_libc_formula?
       false
     end
 
     sig { returns(T::Boolean) }
-    def system_gcc_too_old?
+    def needs_compiler_formula?
       false
     end
 

Library/Homebrew/extend/os/linux/dependency_collector.rb

@@ -13,20 +13,22 @@ class DependencyCollector
   sig { params(related_formula_names: T::Set[String]).returns(T.nilable(Dependency)) }
   def gcc_dep_if_needed(related_formula_names)
     # gcc is required for libgcc_s.so.1 if glibc or gcc are too old
-    return unless DevelopmentTools.build_system_too_old?
+    return unless DevelopmentTools.needs_build_formulae?
     return if building_global_dep_tree?
     return if related_formula_names.include?(GCC)
     return if global_dep_tree[GCC]&.intersect?(related_formula_names)
+    return unless formula_for(GCC)
 
     Dependency.new(GCC)
   end
 
   sig { params(related_formula_names: T::Set[String]).returns(T.nilable(Dependency)) }
   def glibc_dep_if_needed(related_formula_names)
-    return unless OS::Linux::Glibc.below_ci_version?
+    return unless DevelopmentTools.needs_libc_formula?
     return if building_global_dep_tree?
     return if related_formula_names.include?(GLIBC)
     return if global_dep_tree[GLIBC]&.intersect?(related_formula_names)
+    return unless formula_for(GLIBC)
 
     Dependency.new(GLIBC)
   end
@@ -38,7 +40,7 @@ def glibc_dep_if_needed(related_formula_names)
 
   sig { void }
   def init_global_dep_tree_if_needed!
-    return unless DevelopmentTools.build_system_too_old?
+    return unless DevelopmentTools.needs_build_formulae?
     return if building_global_dep_tree?
     return unless global_dep_tree.empty?
 
@@ -49,15 +51,27 @@ def init_global_dep_tree_if_needed!
     built_global_dep_tree!
   end
 
+  sig { params(name: String).returns(T.nilable(Formula)) }
+  def formula_for(name)
+    @formula_for ||= {}
+    @formula_for[name] ||= Formula[name]
+  rescue FormulaUnavailableError
+    nil
+  end
+
   sig { params(name: String).returns(T::Array[String]) }
   def global_deps_for(name)
     @global_deps_for ||= {}
     # Always strip out glibc and gcc from all parts of dependency tree when
     # we're calculating their dependency trees. Other parts of Homebrew will
     # catch any circular dependencies.
-    @global_deps_for[name] ||= Formula[name].deps.map(&:name).flat_map do |dep|
-      [dep, *global_deps_for(dep)].compact
-    end.uniq
+    @global_deps_for[name] ||= if (formula = formula_for(name))
+      formula.deps.map(&:name).flat_map do |dep|
+        [dep, *global_deps_for(dep)].compact
+      end.uniq
+    else
+      []
+    end
   end
 
   # Use class variables to avoid this expensive logic needing to be done more

Library/Homebrew/extend/os/linux/development_tools.rb

@@ -8,10 +8,10 @@ class << self
     sig { params(tool: String).returns(T.nilable(Pathname)) }
     def locate(tool)
       (@locate ||= {}).fetch(tool) do |key|
-        @locate[key] = if build_system_too_old? &&
+        @locate[key] = if needs_build_formulae? &&
                           (binutils_path = HOMEBREW_PREFIX/"opt/binutils/bin/#{tool}").executable?
           binutils_path
-        elsif build_system_too_old? && (glibc_path = HOMEBREW_PREFIX/"opt/glibc/bin/#{tool}").executable?
+        elsif needs_build_formulae? && (glibc_path = HOMEBREW_PREFIX/"opt/glibc/bin/#{tool}").executable?
           glibc_path
         elsif (homebrew_path = HOMEBREW_PREFIX/"bin/#{tool}").executable?
           homebrew_path
@@ -27,18 +27,22 @@ def default_compiler
     end
 
     sig { returns(T::Boolean) }
-    def build_system_too_old?
-      return @build_system_too_old if defined? @build_system_too_old
+    def needs_libc_formula?
+      return @needs_libc_formula if defined? @needs_libc_formula
 
-      @build_system_too_old = (system_gcc_too_old? || OS::Linux::Glibc.below_ci_version?)
+      @needs_libc_formula = OS::Linux::Glibc.below_ci_version?
     end
 
     sig { returns(T::Boolean) }
-    def system_gcc_too_old?
-      gcc = "/usr/bin/gcc"
-      return true unless File.exist?(gcc)
+    def needs_compiler_formula?
+      return @needs_compiler_formula if defined? @needs_compiler_formula
 
-      gcc_version(gcc) < OS::LINUX_GCC_CI_VERSION
+      gcc = "/usr/bin/gcc"
+      @needs_compiler_formula = if File.exist?(gcc)
+        gcc_version(gcc) < OS::LINUX_GCC_CI_VERSION
+      else
+        true
+      end
     end
 
     sig { returns(T::Hash[String, T.nilable(String)]) }

Library/Homebrew/extend/os/linux/formula.rb

@@ -27,7 +27,7 @@ def deuniversalize_machos(*targets); end
 
   sig { params(spec: SoftwareSpec).void }
   def add_global_deps_to_spec(spec)
-    return unless DevelopmentTools.build_system_too_old?
+    return unless DevelopmentTools.needs_build_formulae?
 
     @global_deps ||= begin
       dependency_collector = spec.dependency_collector

Library/Homebrew/formula_installer.rb

@@ -246,7 +246,7 @@ def check_install_sanity
     if Homebrew.default_prefix? &&
        !build_from_source? && !build_bottle? && !formula.head? && formula.tap&.core_tap? &&
        # Integration tests override homebrew-core locations
-       ENV["HOMEBREW_TEST_TMPDIR"].nil? &&
+       ENV["HOMEBREW_INTEGRATION_TEST"].nil? &&
        !pour_bottle?
       message = if !formula.pour_bottle? && formula.pour_bottle_check_unsatisfied_reason
         formula_message = formula.pour_bottle_check_unsatisfied_reason

Library/Homebrew/tap.rb

@@ -797,6 +797,9 @@ def self.ensure_installed!
     return if instance.installed?
     return if Homebrew::EnvConfig.install_from_api?
 
+    # Tests override homebrew-core locations and we don't want to auto-tap in them.
+    return if ENV["HOMEBREW_TESTS"]
+
     safe_system HOMEBREW_BREW_FILE, "tap", instance.name
   end
 

Library/Homebrew/test/caveats_spec.rb

@@ -130,6 +130,11 @@ def plist
     end
 
     context "when f.service is not nil" do
+      before do
+        allow_any_instance_of(Object).to receive(:which).with("launchctl").and_return(true)
+        allow_any_instance_of(Object).to receive(:which).with("systemctl").and_return(true)
+      end
+
       it "prints warning when no service deamon is found" do
         f = formula do
           url "foo-1.0"
@@ -259,6 +264,10 @@ def plist
       let(:path) { f.prefix.resolved_path }
 
       before do
+        # don't try to load/fetch gcc/glibc
+        allow(DevelopmentTools).to receive(:needs_libc_formula?).and_return(false)
+        allow(DevelopmentTools).to receive(:needs_compiler_formula?).and_return(false)
+
         allow_any_instance_of(Pathname).to receive(:children).and_return([Pathname.new("child")])
         allow_any_instance_of(Object).to receive(:which).with(any_args).and_return(Pathname.new("shell"))
         allow(Utils::Shell).to receive(:preferred).and_return(nil)

Library/Homebrew/test/cmd/tap-info_spec.rb

@@ -6,7 +6,7 @@
 describe "brew tap-info" do
   it_behaves_like "parseable arguments"
 
-  it "gets information for a given Tap", :integration_test do
+  it "gets information for a given Tap", :integration_test, :needs_network do
     setup_test_tap
 
     expect { brew "tap-info", "--json=v1", "--installed" }

Library/Homebrew/test/dev-cmd/audit_spec.rb

@@ -1202,6 +1202,9 @@ class FooAT11 < Formula
       end
 
       specify "it warns when another formula does not have a symmetric conflict" do
+        stub_formula_loader formula("gcc") { url "gcc-1.0" }
+        stub_formula_loader formula("glibc") { url "glibc-1.0" }
+
         foo = formula("foo") do
           url "https://brew.sh/foo-1.0.tgz"
         end

Library/Homebrew/test/formula_installer_bottle_spec.rb

@@ -22,9 +22,9 @@ def temporarily_install_bottle(formula)
     expect(formula).to be_bottled
     expect(formula).to pour_bottle
 
-    stub_formula_loader formula
     stub_formula_loader formula("gcc") { url "gcc-1.0" }
-    stub_formula_loader formula("gcc@11") { url "gcc-11.0" }
+    stub_formula_loader formula("glibc") { url "glibc-1.0" }
+    stub_formula_loader formula
 
     fi = FormulaInstaller.new(formula)
     fi.fetch