brew/Library/Homebrew/diagnostic.rb

require "keg"
require "language/python"
require "formula"
require "version"

module Homebrew
  module Diagnostic
    def self.missing_deps(ff)
      missing = {}
      ff.each do |f|
        missing_deps = f.recursive_dependencies do |dependent, dep|
          if dep.optional? || dep.recommended?
            tab = Tab.for_formula(dependent)
            Dependency.prune unless tab.with?(dep)
          elsif dep.build?
            Dependency.prune
          end
        end

        missing_deps.map!(&:to_formula)
        missing_deps.reject! { |d| d.installed_prefixes.any? }

        unless missing_deps.empty?
          yield f.full_name, missing_deps if block_given?
          missing[f.full_name] = missing_deps
        end
      end
      missing
    end

    class Volumes
      def initialize
        @volumes = get_mounts
      end

      def which(path)
        vols = get_mounts path

        # no volume found
        if vols.empty?
          return -1
        end

        vol_index = @volumes.index(vols[0])
        # volume not found in volume list
        if vol_index.nil?
          return -1
        end
        vol_index
      end

      def get_mounts(path = nil)
        vols = []
        # get the volume of path, if path is nil returns all volumes

        args = %w[/bin/df -P]
        args << path if path

        Utils.popen_read(*args) do |io|
          io.each_line do |line|
            case line.chomp
              # regex matches: /dev/disk0s2   489562928 440803616  48247312    91%    /
            when /^.+\s+[0-9]+\s+[0-9]+\s+[0-9]+\s+[0-9]{1,3}%\s+(.+)/
              vols << $1
            end
          end
        end
        vols
      end
    end

    class Checks
      ############# HELPERS
      # Finds files in HOMEBREW_PREFIX *and* /usr/local.
      # Specify paths relative to a prefix eg. "include/foo.h".
      # Sets @found for your convenience.
      def find_relative_paths(*relative_paths)
        @found = [HOMEBREW_PREFIX, "/usr/local"].uniq.inject([]) do |found, prefix|
          found + relative_paths.map { |f| File.join(prefix, f) }.select { |f| File.exist? f }
        end
      end

      def inject_file_list(list, str)
        list.inject(str) { |s, f| s << "    #{f}\n" }
      end
      ############# END HELPERS

      # See https://github.com/Homebrew/legacy-homebrew/pull/9986
      def check_path_for_trailing_slashes
        all_paths = ENV["PATH"].split(File::PATH_SEPARATOR)
        bad_paths = all_paths.select { |p| p[-1..-1] == "/" }
        return if bad_paths.empty?

        inject_file_list bad_paths, <<-EOS.undent
          Some directories in your path end in a slash.
          Directories in your path should not end in a slash. This can break other
          doctor checks. The following directories should be edited:
        EOS
      end

      # Installing MacGPG2 interferes with Homebrew in a big way
      # https://github.com/GPGTools/MacGPG2
      def check_for_macgpg2
        return if File.exist? "/usr/local/MacGPG2/share/gnupg/VERSION"

        suspects = %w[
          /Applications/start-gpg-agent.app
          /Library/Receipts/libiconv1.pkg
          /usr/local/MacGPG2
        ]
        return unless suspects.any? { |f| File.exist? f }

        <<-EOS.undent
          You may have installed MacGPG2 via the package installer.
          Several other checks in this script will turn up problems, such as stray
          dylibs in /usr/local and permissions issues with share and man in /usr/local/.
        EOS
      end

      # Anaconda installs multiple system & brew dupes, including OpenSSL, Python,
      # sqlite, libpng, Qt, etc. Regularly breaks compile on Vim, MacVim and others.
      # Is flagged as part of the *-config script checks below, but people seem
      # to ignore those as warnings rather than extremely likely breakage.
      def check_for_anaconda
        return unless which("anaconda")
        return unless which("python")

        anaconda_directory = which("anaconda").realpath.dirname
        python_binary = Utils.popen_read which("python"), "-c", "import sys; sys.stdout.write(sys.executable)"
        python_directory = Pathname.new(python_binary).realpath.dirname

        # Only warn if Python lives with Anaconda, since is most problematic case.
        return unless python_directory == anaconda_directory

        <<-EOS.undent
          Anaconda is known to frequently break Homebrew builds, including Vim and
          MacVim, due to bundling many duplicates of system and Homebrew-available
          tools.

          If you encounter a build failure please temporarily remove Anaconda
          from your $PATH and attempt the build again prior to reporting the
          failure to us. Thanks!
        EOS
      end

      def __check_stray_files(dir, pattern, white_list, message)
        return unless File.directory?(dir)

        files = Dir.chdir(dir) do
          Dir[pattern].select { |f| File.file?(f) && !File.symlink?(f) } - Dir.glob(white_list)
        end.map { |file| File.join(dir, file) }
        return if files.empty?

        inject_file_list(files, message)
      end

      def check_for_stray_dylibs
        # Dylibs which are generally OK should be added to this list,
        # with a short description of the software they come with.
        white_list = [
          "libfuse.2.dylib", # MacFuse
          "libfuse_ino64.2.dylib", # MacFuse
          "libmacfuse_i32.2.dylib", # OSXFuse MacFuse compatibility layer
          "libmacfuse_i64.2.dylib", # OSXFuse MacFuse compatibility layer
          "libosxfuse_i32.2.dylib", # OSXFuse
          "libosxfuse_i64.2.dylib", # OSXFuse
          "libosxfuse.2.dylib", # OSXFuse
          "libTrAPI.dylib", # TrAPI / Endpoint Security VPN
          "libntfs-3g.*.dylib", # NTFS-3G
          "libntfs.*.dylib", # NTFS-3G
          "libublio.*.dylib", # NTFS-3G
          "libUFSDNTFS.dylib", # Paragon NTFS
          "libUFSDExtFS.dylib", # Paragon ExtFS
        ]

        __check_stray_files "/usr/local/lib", "*.dylib", white_list, <<-EOS.undent
          Unbrewed dylibs were found in /usr/local/lib.
          If you didn't put them there on purpose they could cause problems when
          building Homebrew formulae, and may need to be deleted.

          Unexpected dylibs:
        EOS
      end

      def check_for_stray_static_libs
        # Static libs which are generally OK should be added to this list,
        # with a short description of the software they come with.
        white_list = [
          "libsecurity_agent_client.a", # OS X 10.8.2 Supplemental Update
          "libsecurity_agent_server.a", # OS X 10.8.2 Supplemental Update
          "libntfs-3g.a", # NTFS-3G
          "libntfs.a", # NTFS-3G
          "libublio.a", # NTFS-3G
        ]

        __check_stray_files "/usr/local/lib", "*.a", white_list, <<-EOS.undent
          Unbrewed static libraries were found in /usr/local/lib.
          If you didn't put them there on purpose they could cause problems when
          building Homebrew formulae, and may need to be deleted.

          Unexpected static libraries:
        EOS
      end

      def check_for_stray_pcs
        # Package-config files which are generally OK should be added to this list,
        # with a short description of the software they come with.
        white_list = [
          "fuse.pc", # OSXFuse/MacFuse
          "macfuse.pc", # OSXFuse MacFuse compatibility layer
          "osxfuse.pc", # OSXFuse
          "libntfs-3g.pc", # NTFS-3G
          "libublio.pc", # NTFS-3G
        ]

        __check_stray_files "/usr/local/lib/pkgconfig", "*.pc", white_list, <<-EOS.undent
          Unbrewed .pc files were found in /usr/local/lib/pkgconfig.
          If you didn't put them there on purpose they could cause problems when
          building Homebrew formulae, and may need to be deleted.

          Unexpected .pc files:
        EOS
      end

      def check_for_stray_las
        white_list = [
          "libfuse.la", # MacFuse
          "libfuse_ino64.la", # MacFuse
          "libosxfuse_i32.la", # OSXFuse
          "libosxfuse_i64.la", # OSXFuse
          "libosxfuse.la", # OSXFuse
          "libntfs-3g.la", # NTFS-3G
          "libntfs.la", # NTFS-3G
          "libublio.la", # NTFS-3G
        ]

        __check_stray_files "/usr/local/lib", "*.la", white_list, <<-EOS.undent
          Unbrewed .la files were found in /usr/local/lib.
          If you didn't put them there on purpose they could cause problems when
          building Homebrew formulae, and may need to be deleted.

          Unexpected .la files:
        EOS
      end

      def check_for_stray_headers
        white_list = [
          "fuse.h", # MacFuse
          "fuse/**/*.h", # MacFuse
          "macfuse/**/*.h", # OSXFuse MacFuse compatibility layer
          "osxfuse/**/*.h", # OSXFuse
          "ntfs/**/*.h", # NTFS-3G
          "ntfs-3g/**/*.h", # NTFS-3G
        ]

        __check_stray_files "/usr/local/include", "**/*.h", white_list, <<-EOS.undent
          Unbrewed header files were found in /usr/local/include.
          If you didn't put them there on purpose they could cause problems when
          building Homebrew formulae, and may need to be deleted.

          Unexpected header files:
        EOS
      end

      def check_for_other_package_managers
        ponk = MacOS.macports_or_fink
        return if ponk.empty?

        <<-EOS.undent
          You have MacPorts or Fink installed:
            #{ponk.join(", ")}

          This can cause trouble. You don't have to uninstall them, but you may want to
          temporarily move them out of the way, e.g.

            sudo mv /opt/local ~/macports
        EOS
      end

      def check_for_broken_symlinks
        broken_symlinks = []

        Keg::PRUNEABLE_DIRECTORIES.each do |d|
          next unless d.directory?
          d.find do |path|
            if path.symlink? && !path.resolved_path_exists?
              broken_symlinks << path
            end
          end
        end
        return if broken_symlinks.empty?

        inject_file_list broken_symlinks, <<-EOS.undent
          Broken symlinks were found. Remove them with `brew prune`:
        EOS
      end

      def check_for_unsupported_osx
        return if ARGV.homebrew_developer?

        who = "We"
        if OS::Mac.prerelease?
          what = "pre-release version"
        elsif OS::Mac.outdated_release?
          who << " (and Apple)"
          what = "old version"
        else
          return
        end

        <<-EOS.undent
          You are using OS X #{MacOS.version}.
          #{who} do not provide support for this #{what}.
          You may encounter build failures or other breakages.
        EOS
      end

      # TODO: distill down into single method definition a la BuildToolsError
      if MacOS.version >= "10.9"
        def check_for_installed_developer_tools
          return if MacOS::Xcode.installed? || MacOS::CLT.installed?

          <<-EOS.undent
            No developer tools installed.
            Install the Command Line Tools:
              xcode-select --install
          EOS
        end

        if OS::Mac.prerelease?
          def check_xcode_up_to_date
            return unless MacOS::Xcode.installed? && MacOS::Xcode.outdated?

            <<-EOS.undent
              Your Xcode (#{MacOS::Xcode.version}) is outdated
              Please update to Xcode #{MacOS::Xcode.latest_version}.
              Xcode can be updated from
                https://developer.apple.com/xcode/downloads/
            EOS
          end
        else
          def check_xcode_up_to_date
            return unless MacOS::Xcode.installed? && MacOS::Xcode.outdated?

            <<-EOS.undent
              Your Xcode (#{MacOS::Xcode.version}) is outdated
              Please update to Xcode #{MacOS::Xcode.latest_version}.
              Xcode can be updated from the App Store.
            EOS
          end
        end

        def check_clt_up_to_date
          return unless MacOS::CLT.installed? && MacOS::CLT.outdated?

          <<-EOS.undent
            A newer Command Line Tools release is available.
            Update them from Software Update in the App Store.
          EOS
        end
      elsif MacOS.version == "10.8" || MacOS.version == "10.7"
        def check_for_installed_developer_tools
          return if MacOS::Xcode.installed? || MacOS::CLT.installed?

          <<-EOS.undent
            No developer tools installed.
            You should install the Command Line Tools.
            The standalone package can be obtained from
              https://developer.apple.com/downloads
            or it can be installed via Xcode's preferences.
          EOS
        end

        def check_xcode_up_to_date
          return unless MacOS::Xcode.installed? && MacOS::Xcode.outdated?

          <<-EOS.undent
            Your Xcode (#{MacOS::Xcode.version}) is outdated
            Please update to Xcode #{MacOS::Xcode.latest_version}.
            Xcode can be updated from
              https://developer.apple.com/xcode/downloads/
          EOS
        end

        def check_clt_up_to_date
          return unless MacOS::CLT.installed? && MacOS::CLT.outdated?

          <<-EOS.undent
            A newer Command Line Tools release is available.
            The standalone package can be obtained from
              https://developer.apple.com/downloads
            or it can be installed via Xcode's preferences.
          EOS
        end
      else
        def check_for_installed_developer_tools
          return if MacOS::Xcode.installed?

          <<-EOS.undent
            Xcode is not installed. Most formulae need Xcode to build.
            It can be installed from
              https://developer.apple.com/xcode/downloads/
          EOS
        end

        def check_xcode_up_to_date
          return unless MacOS::Xcode.installed? && MacOS::Xcode.outdated?

          <<-EOS.undent
            Your Xcode (#{MacOS::Xcode.version}) is outdated
            Please update to Xcode #{MacOS::Xcode.latest_version}.
            Xcode can be updated from
              https://developer.apple.com/xcode/downloads/
          EOS
        end
      end

      def check_for_osx_gcc_installer
        return unless MacOS.version < "10.7" || ((MacOS::Xcode.version || "0") > "4.1")
        return unless MacOS.clang_version == "2.1"

        fix_advice = if MacOS.version >= :mavericks
          "Please run `xcode-select --install` to install the CLT."
        elsif MacOS.version >= :lion
          "Please install the CLT or Xcode #{MacOS::Xcode.latest_version}."
        else
          "Please install Xcode #{MacOS::Xcode.latest_version}."
        end

        <<-EOS.undent
          You seem to have osx-gcc-installer installed.
          Homebrew doesn't support osx-gcc-installer. It causes many builds to fail and
          is an unlicensed distribution of really old Xcode files.
          #{fix_advice}
        EOS
      end

      def check_for_stray_developer_directory
        # if the uninstaller script isn't there, it's a good guess neither are
        # any troublesome leftover Xcode files
        uninstaller = Pathname.new("/Developer/Library/uninstall-developer-folder")
        return unless ((MacOS::Xcode.version || "0") >= "4.3") && uninstaller.exist?

        <<-EOS.undent
          You have leftover files from an older version of Xcode.
          You should delete them using:
            #{uninstaller}
        EOS
      end

      def check_for_bad_install_name_tool
        return if MacOS.version < "10.9"

        libs = Pathname.new("/usr/bin/install_name_tool").dynamically_linked_libraries

        # otool may not work, for example if the Xcode license hasn't been accepted yet
        return if libs.empty?
        return if libs.include? "/usr/lib/libxcselect.dylib"

        <<-EOS.undent
          You have an outdated version of /usr/bin/install_name_tool installed.
          This will cause binary package installations to fail.
          This can happen if you install osx-gcc-installer or RailsInstaller.
          To restore it, you must reinstall OS X or restore the binary from
          the OS packages.
        EOS
      end

      def __check_subdir_access(base)
        target = HOMEBREW_PREFIX+base
        return unless target.exist?

        cant_read = []
        target.find do |d|
          next unless d.directory?
          cant_read << d unless d.writable_real?
        end
        return if cant_read.empty?

        inject_file_list cant_read.sort, <<-EOS.undent
          Some directories in #{target} aren't writable.
          This can happen if you "sudo make install" software that isn't managed
          by Homebrew. If a brew tries to add locale information to one of these
          directories, then the install will fail during the link step.

          You should probably `sudo chown -R $(whoami)` them:
        EOS
      end

      def check_access_share_locale
        __check_subdir_access "share/locale"
      end

      def check_access_share_man
        __check_subdir_access "share/man"
      end

      def check_access_homebrew_repository
        return if HOMEBREW_REPOSITORY.writable_real?

        <<-EOS.undent
          #{HOMEBREW_REPOSITORY} is not writable.

          You should probably change the ownership and permissions of #{HOMEBREW_REPOSITORY}
          back to your user account.
            sudo chown -R $(whoami) #{HOMEBREW_REPOSITORY}
        EOS
      end

      def check_access_usr_local
        return unless HOMEBREW_PREFIX.to_s == "/usr/local"
        return if HOMEBREW_PREFIX.writable_real?

        <<-EOS.undent
          /usr/local is not writable.
          Even if this directory was writable when you installed Homebrew, other
          software may change permissions on this directory. For example, upgrading
          to OS X El Capitan has been known to do this. Some versions of the
          "InstantOn" component of Airfoil or running Cocktail cleanup/optimizations
          are known to do this as well.

          You should probably change the ownership and permissions of /usr/local
          back to your user account.
            sudo chown -R $(whoami) /usr/local
        EOS
      end

      def check_tmpdir_sticky_bit
        world_writable = HOMEBREW_TEMP.stat.mode & 0777 == 0777
        return if !world_writable || HOMEBREW_TEMP.sticky?

        # Repair Disk Permissions was removed in El Capitan.
        # https://support.apple.com/en-us/HT201560
        fix_advice = if MacOS.version < "10.11"
          "Please run \"Repair Disk Permissions\" in Disk Utility."
        else
          "Please execute `sudo chmod +t #{HOMEBREW_TEMP}` in your Terminal."
        end

        <<-EOS.undent
          #{HOMEBREW_TEMP} is world-writable but does not have the sticky bit set.
          #{fix_advice}
        EOS
      end

      (Keg::TOP_LEVEL_DIRECTORIES + ["lib/pkgconfig"]).each do |d|
        define_method("check_access_#{d.sub("/", "_")}") do
          dir = HOMEBREW_PREFIX.join(d)
          return unless dir.exist?
          return if dir.writable_real?

          <<-EOS.undent
            #{dir} isn't writable.

            This can happen if you "sudo make install" software that isn't managed
            by Homebrew. If a formula tries to write a file to this directory, the
            install will fail during the link step.

            You should probably change the ownership and permissions of #{dir}
            back to your user account.
              sudo chown -R $(whoami) #{dir}
          EOS
        end
      end

      def check_access_site_packages
        return unless Language::Python.homebrew_site_packages.exist?
        return if Language::Python.homebrew_site_packages.writable_real?

        <<-EOS.undent
          #{Language::Python.homebrew_site_packages} isn't writable.
          This can happen if you "sudo pip install" software that isn't managed
          by Homebrew. If you install a formula with Python modules, the install
          will fail during the link step.

          You should probably change the ownership and permissions of #{Language::Python.homebrew_site_packages}
          back to your user account.
            sudo chown -R $(whoami) #{Language::Python.homebrew_site_packages}
        EOS
      end

      def check_access_logs
        return unless HOMEBREW_LOGS.exist?
        return if HOMEBREW_LOGS.writable_real?

        <<-EOS.undent
          #{HOMEBREW_LOGS} isn't writable.
          Homebrew writes debugging logs to this location.

          You should probably change the ownership and permissions of #{HOMEBREW_LOGS}
          back to your user account.
            sudo chown -R $(whoami) #{HOMEBREW_LOGS}
        EOS
      end

      def check_access_cache
        return unless HOMEBREW_CACHE.exist?
        return if HOMEBREW_CACHE.writable_real?

        <<-EOS.undent
          #{HOMEBREW_CACHE} isn't writable.
          This can happen if you run `brew install` or `brew fetch` as another user.
          Homebrew caches downloaded files to this location.

          You should probably change the ownership and permissions of #{HOMEBREW_CACHE}
          back to your user account.
            sudo chown -R $(whoami) #{HOMEBREW_CACHE}
        EOS
      end

      def check_access_cellar
        return unless HOMEBREW_CELLAR.exist?
        return if HOMEBREW_CELLAR.writable_real?

        <<-EOS.undent
          #{HOMEBREW_CELLAR} isn't writable.

          You should probably change the ownership and permissions of #{HOMEBREW_CELLAR}
          back to your user account.
            sudo chown -R $(whoami) #{HOMEBREW_CELLAR}
        EOS
      end

      def check_access_prefix_opt
        opt = HOMEBREW_PREFIX.join("opt")
        return unless opt.exist?
        return if opt.writable_real?

        <<-EOS.undent
          #{opt} isn't writable.

          You should probably change the ownership and permissions of #{opt}
          back to your user account.
            sudo chown -R $(whoami) #{opt}
        EOS
      end

      def check_ruby_version
        ruby_version = MacOS.version >= "10.9" ? "2.0" : "1.8"
        return if RUBY_VERSION[/\d\.\d/] == ruby_version

        <<-EOS.undent
          Ruby version #{RUBY_VERSION} is unsupported on #{MacOS.version}. Homebrew
          is developed and tested on Ruby #{ruby_version}, and may not work correctly
          on other Rubies. Patches are accepted as long as they don't cause breakage
          on supported Rubies.
        EOS
      end

      def check_homebrew_prefix
        return if HOMEBREW_PREFIX.to_s == "/usr/local"

        <<-EOS.undent
          Your Homebrew is not installed to /usr/local
          You can install Homebrew anywhere you want, but some brews may only build
          correctly if you install in /usr/local. Sorry!
        EOS
      end

      def check_xcode_prefix
        prefix = MacOS::Xcode.prefix
        return if prefix.nil?
        return unless prefix.to_s.include?(" ")

        <<-EOS.undent
          Xcode is installed to a directory with a space in the name.
          This will cause some formulae to fail to build.
        EOS
      end

      def check_xcode_prefix_exists
        prefix = MacOS::Xcode.prefix
        return if prefix.nil? || prefix.exist?

        <<-EOS.undent
          The directory Xcode is reportedly installed to doesn't exist:
            #{prefix}
          You may need to `xcode-select` the proper path if you have moved Xcode.
        EOS
      end

      def check_xcode_select_path
        return if MacOS::CLT.installed?
        return if File.file?("#{MacOS.active_developer_dir}/usr/bin/xcodebuild")

        path = MacOS::Xcode.bundle_path
        path = "/Developer" if path.nil? || !path.directory?
        <<-EOS.undent
          Your Xcode is configured with an invalid path.
          You should change it to the correct path:
            sudo xcode-select -switch #{path}
        EOS
      end

      def check_user_path_1
        $seen_prefix_bin = false
        $seen_prefix_sbin = false

        message = ""

        paths.each do |p|
          case p
          when "/usr/bin"
            unless $seen_prefix_bin
              # only show the doctor message if there are any conflicts
              # rationale: a default install should not trigger any brew doctor messages
              conflicts = Dir["#{HOMEBREW_PREFIX}/bin/*"].
                          map { |fn| File.basename fn }.
                          select { |bn| File.exist? "/usr/bin/#{bn}" }

              if conflicts.size > 0
                message = inject_file_list conflicts, <<-EOS.undent
                  /usr/bin occurs before #{HOMEBREW_PREFIX}/bin
                  This means that system-provided programs will be used instead of those
                  provided by Homebrew. The following tools exist at both paths:
                EOS

                message += <<-EOS.undent

                  Consider setting your PATH so that #{HOMEBREW_PREFIX}/bin
                  occurs before /usr/bin. Here is a one-liner:
                    echo 'export PATH="#{HOMEBREW_PREFIX}/bin:$PATH"' >> #{shell_profile}
                EOS
              end
            end
          when "#{HOMEBREW_PREFIX}/bin"
            $seen_prefix_bin = true
          when "#{HOMEBREW_PREFIX}/sbin"
            $seen_prefix_sbin = true
          end
        end

        message unless message.empty?
      end

      def check_user_path_2
        return if $seen_prefix_bin

        <<-EOS.undent
          Homebrew's bin was not found in your PATH.
          Consider setting the PATH for example like so
            echo 'export PATH="#{HOMEBREW_PREFIX}/bin:$PATH"' >> #{shell_profile}
        EOS
      end

      def check_user_path_3
        return if $seen_prefix_sbin

        # Don't complain about sbin not being in the path if it doesn't exist
        sbin = (HOMEBREW_PREFIX+"sbin")
        return unless sbin.directory? && sbin.children.length > 0

        <<-EOS.undent
          Homebrew's sbin was not found in your PATH but you have installed
          formulae that put executables in #{HOMEBREW_PREFIX}/sbin.
          Consider setting the PATH for example like so
            echo 'export PATH="#{HOMEBREW_PREFIX}/sbin:$PATH"' >> #{shell_profile}
        EOS
      end

      def check_for_bad_curl
        return unless MacOS.version <= "10.8"
        return if Formula["curl"].installed?

        <<-EOS.undent
          The system curl on 10.8 and below is often incapable of supporting
          modern secure connections & will fail on fetching formulae.

          We recommend you:
            brew install curl
        EOS
      end

      def check_user_curlrc
        curlrc_found = %w[CURL_HOME HOME].any? do |var|
          ENV[var] && File.exist?("#{ENV[var]}/.curlrc")
        end
        return unless curlrc_found

        <<-EOS.undent
          You have a curlrc file
          If you have trouble downloading packages with Homebrew, then maybe this
          is the problem? If the following command doesn't work, then try removing
          your curlrc:
            curl https://github.com
        EOS
      end

      def check_for_unsupported_curl_vars
        # Support for SSL_CERT_DIR seemed to be removed in the 10.10.5 update.
        return unless MacOS.version >= :yosemite
        return if ENV["SSL_CERT_DIR"].nil?

        <<-EOS.undent
          SSL_CERT_DIR support was removed from Apple's curl.
          If fetching formulae fails you should:
            unset SSL_CERT_DIR
          and remove it from #{shell_profile} if present.
        EOS
      end

      def check_which_pkg_config
        binary = which "pkg-config"
        return if binary.nil?

        mono_config = Pathname.new("/usr/bin/pkg-config")
        if mono_config.exist? && mono_config.realpath.to_s.include?("Mono.framework")
          <<-EOS.undent
            You have a non-Homebrew 'pkg-config' in your PATH:
              /usr/bin/pkg-config => #{mono_config.realpath}

            This was most likely created by the Mono installer. `./configure` may
            have problems finding brew-installed packages using this other pkg-config.

            Mono no longer installs this file as of 3.0.4. You should
            `sudo rm /usr/bin/pkg-config` and upgrade to the latest version of Mono.
          EOS
        elsif binary.to_s != "#{HOMEBREW_PREFIX}/bin/pkg-config"
          <<-EOS.undent
            You have a non-Homebrew 'pkg-config' in your PATH:
              #{binary}

            `./configure` may have problems finding brew-installed packages using
            this other pkg-config.
          EOS
        end
      end

      def check_for_gettext
        find_relative_paths("lib/libgettextlib.dylib",
                            "lib/libintl.dylib",
                            "include/libintl.h")
        return if @found.empty?

        # Our gettext formula will be caught by check_linked_keg_only_brews
        gettext = Formulary.factory("gettext") rescue nil
        homebrew_owned = @found.all? do |path|
          Pathname.new(path).realpath.to_s.start_with? "#{HOMEBREW_CELLAR}/gettext"
        end
        return if gettext && gettext.linked_keg.directory? && homebrew_owned

        inject_file_list @found, <<-EOS.undent
          gettext files detected at a system prefix.
          These files can cause compilation and link failures, especially if they
          are compiled with improper architectures. Consider removing these files:
        EOS
      end

      def check_for_iconv
        find_relative_paths("lib/libiconv.dylib", "include/iconv.h")
        return if @found.empty?

        libiconv = Formulary.factory("libiconv") rescue nil
        if libiconv && libiconv.linked_keg.directory?
          unless libiconv.keg_only?
            <<-EOS.undent
              A libiconv formula is installed and linked.
              This will break stuff. For serious. Unlink it.
            EOS
          end
        else
          inject_file_list @found, <<-EOS.undent
            libiconv files detected at a system prefix other than /usr.
            Homebrew doesn't provide a libiconv formula, and expects to link against
            the system version in /usr. libiconv in other prefixes can cause
            compile or link failure, especially if compiled with improper
            architectures. OS X itself never installs anything to /usr/local so
            it was either installed by a user or some other third party software.

            tl;dr: delete these files:
          EOS
        end
      end

      def check_for_config_scripts
        return unless HOMEBREW_CELLAR.exist?
        real_cellar = HOMEBREW_CELLAR.realpath

        scripts = []

        whitelist = %W[
          /usr/bin /usr/sbin
          /usr/X11/bin /usr/X11R6/bin /opt/X11/bin
          #{HOMEBREW_PREFIX}/bin #{HOMEBREW_PREFIX}/sbin
          /Applications/Server.app/Contents/ServerRoot/usr/bin
          /Applications/Server.app/Contents/ServerRoot/usr/sbin
        ].map(&:downcase)

        paths.each do |p|
          next if whitelist.include?(p.downcase) || !File.directory?(p)

          realpath = Pathname.new(p).realpath.to_s
          next if realpath.start_with?(real_cellar.to_s, HOMEBREW_CELLAR.to_s)

          scripts += Dir.chdir(p) { Dir["*-config"] }.map { |c| File.join(p, c) }
        end

        return if scripts.empty?

        inject_file_list scripts, <<-EOS.undent
          "config" scripts exist outside your system or Homebrew directories.
          `./configure` scripts often look for *-config scripts to determine if
          software packages are installed, and what additional flags to use when
          compiling and linking.

          Having additional scripts in your path can confuse software installed via
          Homebrew if the config script overrides a system or Homebrew provided
          script of the same name. We found the following "config" scripts:
        EOS
      end

      def check_DYLD_vars
        dyld_vars = ENV.keys.grep(/^DYLD_/)
        return if dyld_vars.empty?

        values = dyld_vars.map { |var| "#{var}: #{ENV.fetch(var)}" }
        message = inject_file_list values, <<-EOS.undent
          Setting DYLD_* vars can break dynamic linking.
          Set variables:
        EOS

        if dyld_vars.include? "DYLD_INSERT_LIBRARIES"
          message += <<-EOS.undent

            Setting DYLD_INSERT_LIBRARIES can cause Go builds to fail.
            Having this set is common if you use this software:
              http://asepsis.binaryage.com/
          EOS
        end

        message
      end

      def check_for_symlinked_cellar
        return unless HOMEBREW_CELLAR.exist?
        return unless HOMEBREW_CELLAR.symlink?

        <<-EOS.undent
          Symlinked Cellars can cause problems.
          Your Homebrew Cellar is a symlink: #{HOMEBREW_CELLAR}
                          which resolves to: #{HOMEBREW_CELLAR.realpath}

          The recommended Homebrew installations are either:
          (A) Have Cellar be a real directory inside of your HOMEBREW_PREFIX
          (B) Symlink "bin/brew" into your prefix, but don't symlink "Cellar".

          Older installations of Homebrew may have created a symlinked Cellar, but this can
          cause problems when two formula install to locations that are mapped on top of each
          other during the linking step.
        EOS
      end

      def check_for_multiple_volumes
        return unless HOMEBREW_CELLAR.exist?
        volumes = Volumes.new

        # Find the volumes for the TMP folder & HOMEBREW_CELLAR
        real_cellar = HOMEBREW_CELLAR.realpath
        where_cellar = volumes.which real_cellar

        tmp = Pathname.new(Dir.mktmpdir("doctor", HOMEBREW_TEMP))
        begin
          real_tmp = tmp.realpath.parent
          where_tmp = volumes.which real_tmp
        ensure
          Dir.delete tmp
        end
        return if where_cellar == where_tmp

        <<-EOS.undent
          Your Cellar and TEMP directories are on different volumes.
          OS X won't move relative symlinks across volumes unless the target file already
          exists. Brews known to be affected by this are Git and Narwhal.

          You should set the "HOMEBREW_TEMP" environmental variable to a suitable
          directory on the same volume as your Cellar.
        EOS
      end

      def check_filesystem_case_sensitive
        dirs_to_check = [
          HOMEBREW_PREFIX,
          HOMEBREW_REPOSITORY,
          HOMEBREW_CELLAR,
          HOMEBREW_TEMP,
        ]
        case_sensitive_dirs = dirs_to_check.select do |dir|
          # We select the dir as being case-sensitive if either the UPCASED or the
          # downcased variant is missing.
          # Of course, on a case-insensitive fs, both exist because the os reports so.
          # In the rare situation when the user has indeed a downcased and an upcased
          # dir (e.g. /TMP and /tmp) this check falsely thinks it is case-insensitive
          # but we don't care because: 1. there is more than one dir checked, 2. the
          # check is not vital and 3. we would have to touch files otherwise.
          upcased = Pathname.new(dir.to_s.upcase)
          downcased = Pathname.new(dir.to_s.downcase)
          dir.exist? && !(upcased.exist? && downcased.exist?)
        end
        return if case_sensitive_dirs.empty?

        volumes = Volumes.new
        case_sensitive_vols = case_sensitive_dirs.map do |case_sensitive_dir|
          volumes.get_mounts(case_sensitive_dir)
        end
        case_sensitive_vols.uniq!

        <<-EOS.undent
          The filesystem on #{case_sensitive_vols.join(",")} appears to be case-sensitive.
          The default OS X filesystem is case-insensitive. Please report any apparent problems.
        EOS
      end

      def __check_git_version
        # https://help.github.com/articles/https-cloning-errors
        `git --version`.chomp =~ /git version ((?:\d+\.?)+)/
        return unless $1 && Version.new($1) < Version.new("1.7.10")

        git = Formula["git"]
        git_upgrade_cmd = git.any_version_installed? ? "upgrade" : "install"
        <<-EOS.undent
          An outdated version of Git was detected in your PATH.
          Git 1.7.10 or newer is required to perform checkouts over HTTPS from GitHub.
          Please upgrade:
            brew #{git_upgrade_cmd} git
        EOS
      end

      def check_for_git
        if Utils.git_available?
          __check_git_version
        else
          <<-EOS.undent
            Git could not be found in your PATH.
            Homebrew uses Git for several internal functions, and some formulae use Git
            checkouts instead of stable tarballs. You may want to install Git:
              brew install git
          EOS
        end
      end

      def check_git_newline_settings
        return unless Utils.git_available?

        autocrlf = HOMEBREW_REPOSITORY.cd { `git config --get core.autocrlf`.chomp }
        return unless autocrlf == "true"

        <<-EOS.undent
          Suspicious Git newline settings found.

          The detected Git newline settings will cause checkout problems:
            core.autocrlf = #{autocrlf}

          If you are not routinely dealing with Windows-based projects,
          consider removing these by running:
            git config --global core.autocrlf input
        EOS
      end

      def check_git_origin
        return if !Utils.git_available? || !(HOMEBREW_REPOSITORY/".git").exist?

        origin = Homebrew.git_origin

        if origin.nil?
          <<-EOS.undent
            Missing git origin remote.

            Without a correctly configured origin, Homebrew won't update
            properly. You can solve this by adding the Homebrew remote:
              cd #{HOMEBREW_REPOSITORY}
              git remote add origin https://github.com/Homebrew/brew.git
          EOS
        elsif origin !~ /Homebrew\/brew(\.git)?$/
          <<-EOS.undent
            Suspicious git origin remote found.

            With a non-standard origin, Homebrew won't pull updates from
            the main repository. The current git origin is:
              #{origin}

            Unless you have compelling reasons, consider setting the
            origin remote to point at the main repository, located at:
              https://github.com/Homebrew/brew.git
          EOS
        end
      end

      def __check_linked_brew(f)
        f.installed_prefixes.each do |prefix|
          prefix.find do |src|
            next if src == prefix
            dst = HOMEBREW_PREFIX + src.relative_path_from(prefix)
            return true if dst.symlink? && src == dst.resolved_path
          end
        end

        false
      end

      def check_for_linked_keg_only_brews
        return unless HOMEBREW_CELLAR.exist?

        linked = Formula.installed.select do |f|
          f.keg_only? && __check_linked_brew(f)
        end
        return if linked.empty?

        inject_file_list linked.map(&:full_name), <<-EOS.undent
          Some keg-only formula are linked into the Cellar.
          Linking a keg-only formula, such as gettext, into the cellar with
          `brew link <formula>` will cause other formulae to detect them during
          the `./configure` step. This may cause problems when compiling those
          other formulae.

          Binaries provided by keg-only formulae may override system binaries
          with other strange results.

          You may wish to `brew unlink` these brews:
        EOS
      end

      def check_for_other_frameworks
        # Other frameworks that are known to cause problems when present
        frameworks_to_check = %w[
          expat.framework
          libexpat.framework
          libcurl.framework
        ]
        frameworks_found = frameworks_to_check.
          map { |framework| "/Library/Frameworks/#{framework}" }.
          select { |framework| File.exist? framework }
        return if frameworks_found.empty?

        inject_file_list frameworks_found, <<-EOS.undent
          Some frameworks can be picked up by CMake's build system and likely
          cause the build to fail. To compile CMake, you may wish to move these
          out of the way:
        EOS
      end

      def check_tmpdir
        tmpdir = ENV["TMPDIR"]
        return if tmpdir.nil? || File.directory?(tmpdir)

        <<-EOS.undent
          TMPDIR #{tmpdir.inspect} doesn't exist.
        EOS
      end

      def check_missing_deps
        return unless HOMEBREW_CELLAR.exist?
        missing = Set.new
        Homebrew::Diagnostic.missing_deps(Formula.installed).each_value do |deps|
          missing.merge(deps)
        end
        return if missing.empty?

        <<-EOS.undent
          Some installed formula are missing dependencies.
          You should `brew install` the missing dependencies:
            brew install #{missing.sort_by(&:full_name) * " "}

          Run `brew missing` for more details.
        EOS
      end

      def check_git_status
        return unless Utils.git_available?
        HOMEBREW_REPOSITORY.cd do
          return if `git status --untracked-files=all --porcelain -- Library/Homebrew/ 2>/dev/null`.chomp.empty?
        end

        <<-EOS.undent
          You have uncommitted modifications to Homebrew
          If this is a surprise to you, then you should stash these modifications.
          Stashing returns Homebrew to a pristine state but can be undone
          should you later need to do so for some reason.
            cd #{HOMEBREW_LIBRARY} && git stash && git clean -d -f
        EOS
      end

      def check_for_enthought_python
        return unless which "enpkg"

        <<-EOS.undent
          Enthought Python was found in your PATH.
          This can cause build problems, as this software installs its own
          copies of iconv and libxml2 into directories that are picked up by
          other build systems.
        EOS
      end

      def check_for_library_python
        return unless File.exist?("/Library/Frameworks/Python.framework")

        <<-EOS.undent
          Python is installed at /Library/Frameworks/Python.framework

          Homebrew only supports building against the System-provided Python or a
          brewed Python. In particular, Pythons installed to /Library can interfere
          with other software installs.
        EOS
      end

      def check_for_old_homebrew_share_python_in_path
        message = ""
        ["", "3"].map do |suffix|
          if paths.include?((HOMEBREW_PREFIX/"share/python#{suffix}").to_s)
            message += <<-EOS.undent
              #{HOMEBREW_PREFIX}/share/python#{suffix} is not needed in PATH.
            EOS
          end
        end
        unless message.empty?
          message += <<-EOS.undent

            Formerly homebrew put Python scripts you installed via `pip` or `pip3`
            (or `easy_install`) into that directory above but now it can be removed
            from your PATH variable.
            Python scripts will now install into #{HOMEBREW_PREFIX}/bin.
            You can delete anything, except 'Extras', from the #{HOMEBREW_PREFIX}/share/python
            (and #{HOMEBREW_PREFIX}/share/python3) dir and install affected Python packages
            anew with `pip install --upgrade`.
          EOS
        end

        message unless message.empty?
      end

      def check_for_bad_python_symlink
        return unless which "python"
        `python -V 2>&1` =~ /Python (\d+)\./
        # This won't be the right warning if we matched nothing at all
        return if $1.nil?
        return if $1 == "2"

        <<-EOS.undent
          python is symlinked to python#{$1}
          This will confuse build scripts and in general lead to subtle breakage.
        EOS
      end

      def check_for_non_prefixed_coreutils
        coreutils = Formula["coreutils"]
        return unless coreutils.any_version_installed?

        gnubin = %W[#{coreutils.opt_libexec}/gnubin #{coreutils.libexec}/gnubin]
        return if (paths & gnubin).empty?

        <<-EOS.undent
          Putting non-prefixed coreutils in your path can cause gmp builds to fail.
        EOS
      end

      def check_for_non_prefixed_findutils
        findutils = Formula["findutils"]
        return unless findutils.any_version_installed?

        gnubin = %W[#{findutils.opt_libexec}/gnubin #{findutils.libexec}/gnubin]
        default_names = Tab.for_name("findutils").with? "default-names"
        return if !default_names && (paths & gnubin).empty?

        <<-EOS.undent
          Putting non-prefixed findutils in your path can cause python builds to fail.
        EOS
      end

      def check_for_pydistutils_cfg_in_home
        return unless File.exist? "#{ENV["HOME"]}/.pydistutils.cfg"

        <<-EOS.undent
          A .pydistutils.cfg file was found in $HOME, which may cause Python
          builds to fail. See:
            https://bugs.python.org/issue6138
            https://bugs.python.org/issue4655
        EOS
      end

      def check_for_outdated_homebrew
        return unless Utils.git_available?

        timestamp = if File.directory?("#{HOMEBREW_REPOSITORY}/.git")
          HOMEBREW_REPOSITORY.cd { `git log -1 --format="%ct" HEAD`.to_i }
        else
          HOMEBREW_LIBRARY.mtime.to_i
        end
        return if Time.now.to_i - timestamp <= 60 * 60 * 24 # 24 hours

        if File.directory?("#{HOMEBREW_REPOSITORY}/.git")
          HOMEBREW_REPOSITORY.cd do
            local = `git rev-parse -q --verify refs/remotes/origin/master`.chomp
            remote = /^([a-f0-9]{40})/.match(`git ls-remote origin refs/heads/master 2>/dev/null`)
            return if remote.nil? || local == remote[0]
          end
        end

        <<-EOS.undent
          Your Homebrew is outdated.
          You haven't updated for at least 24 hours. This is a long time in brewland!
          To update Homebrew, run `brew update`.
        EOS
      end

      def check_for_unlinked_but_not_keg_only
        unlinked = Formula.racks.reject do |rack|
          if !(HOMEBREW_REPOSITORY/"Library/LinkedKegs"/rack.basename).directory?
            begin
              Formulary.from_rack(rack).keg_only?
            rescue FormulaUnavailableError, TapFormulaAmbiguityError, TapFormulaWithOldnameAmbiguityError
              false
            end
          else
            true
          end
        end.map(&:basename)
        return if unlinked.empty?

        inject_file_list unlinked, <<-EOS.undent
          You have unlinked kegs in your Cellar
          Leaving kegs unlinked can lead to build-trouble and cause brews that depend on
          those kegs to fail to run properly once built. Run `brew link` on these:
        EOS
      end

      def check_xcode_license_approved
        # If the user installs Xcode-only, they have to approve the
        # license or no "xc*" tool will work.
        return unless `/usr/bin/xcrun clang 2>&1` =~ /license/ && !$?.success?

        <<-EOS.undent
          You have not agreed to the Xcode license.
          Builds will fail! Agree to the license by opening Xcode.app or running:
            sudo xcodebuild -license
        EOS
      end

      def check_for_latest_xquartz
        return unless MacOS::XQuartz.version
        return if MacOS::XQuartz.provided_by_apple?

        installed_version = Version.new(MacOS::XQuartz.version)
        latest_version = Version.new(MacOS::XQuartz.latest_version)
        return if installed_version >= latest_version

        <<-EOS.undent
          Your XQuartz (#{installed_version}) is outdated
          Please install XQuartz #{latest_version}:
            https://xquartz.macosforge.org
        EOS
      end

      def check_for_old_env_vars
        return unless ENV["HOMEBREW_KEEP_INFO"]

        <<-EOS.undent
          `HOMEBREW_KEEP_INFO` is no longer used
          info files are no longer deleted by default; you may
          remove this environment variable.
        EOS
      end

      def check_for_pth_support
        homebrew_site_packages = Language::Python.homebrew_site_packages
        return unless homebrew_site_packages.directory?
        return if Language::Python.reads_brewed_pth_files?("python") != false
        return unless Language::Python.in_sys_path?("python", homebrew_site_packages)

        user_site_packages = Language::Python.user_site_packages "python"
        <<-EOS.undent
          Your default Python does not recognize the Homebrew site-packages
          directory as a special site-packages directory, which means that .pth
          files will not be followed. This means you will not be able to import
          some modules after installing them with Homebrew, like wxpython. To fix
          this for the current user, you can run:
            mkdir -p #{user_site_packages}
            echo 'import site; site.addsitedir("#{homebrew_site_packages}")' >> #{user_site_packages}/homebrew.pth
        EOS
      end

      def check_for_external_cmd_name_conflict
        cmds = paths.flat_map { |p| Dir["#{p}/brew-*"] }.uniq
        cmds = cmds.select { |cmd| File.file?(cmd) && File.executable?(cmd) }
        cmd_map = {}
        cmds.each do |cmd|
          cmd_name = File.basename(cmd, ".rb")
          cmd_map[cmd_name] ||= []
          cmd_map[cmd_name] << cmd
        end
        cmd_map.reject! { |_cmd_name, cmd_paths| cmd_paths.size == 1 }
        return if cmd_map.empty?

        message = "You have external commands with conflicting names.\n"
        cmd_map.each do |cmd_name, cmd_paths|
          message += inject_file_list cmd_paths, <<-EOS.undent

            Found command `#{cmd_name}` in following places:
          EOS
        end

        message
      end

      def all
        methods.map(&:to_s).grep(/^check_/)
      end
    end # end class Checks
  end
end