Merge pull request #4557 from MikeMcQuaid/no-link-caveats-output

link: when refusing to link display keg only caveats instead.

Library/Homebrew/caveats.rb

@@ -30,6 +30,64 @@ class Caveats
 
   delegate [:empty?, :to_s] => :caveats
 
+  def keg_only_text(skip_reason: false)
+    return unless f.keg_only?
+
+    s = if skip_reason
+      ""
+    else
+      <<~EOS
+        #{f.name} is keg-only, which means it was not symlinked into #{HOMEBREW_PREFIX},
+        because #{f.keg_only_reason.to_s.chomp}.
+      EOS
+    end
+
+    if f.bin.directory? || f.sbin.directory?
+      s << <<~EOS
+
+        If you need to have #{f.name} first in your PATH run:
+      EOS
+      if f.bin.directory?
+        s << "  #{Utils::Shell.prepend_path_in_profile(f.opt_bin.to_s)}\n"
+      end
+      if f.sbin.directory?
+        s << "  #{Utils::Shell.prepend_path_in_profile(f.opt_sbin.to_s)}\n"
+      end
+    end
+
+    if f.lib.directory? || f.include.directory?
+      s << <<~EOS
+
+        For compilers to find #{f.name} you may need to set:
+      EOS
+
+      if f.lib.directory?
+        s << "  #{Utils::Shell.export_value("LDFLAGS", "-L#{f.opt_lib}")}\n"
+      end
+
+      if f.include.directory?
+        s << "  #{Utils::Shell.export_value("CPPFLAGS", "-I#{f.opt_include}")}\n"
+      end
+
+      if which("pkg-config", ENV["HOMEBREW_PATH"]) &&
+         ((f.lib/"pkgconfig").directory? || (f.share/"pkgconfig").directory?)
+        s << <<~EOS
+
+          For pkg-config to find #{f.name} you may need to set:
+        EOS
+
+        if (f.lib/"pkgconfig").directory?
+          s << "  #{Utils::Shell.export_value("PKG_CONFIG_PATH", "#{f.opt_lib}/pkgconfig")}\n"
+        end
+
+        if (f.share/"pkgconfig").directory?
+          s << "  #{Utils::Shell.export_value("PKG_CONFIG_PATH", "#{f.opt_share}/pkgconfig")}\n"
+        end
+      end
+    end
+    s << "\n"
+  end
+
   private
 
   def keg
@@ -42,37 +100,6 @@ class Caveats
     end.compact.first
   end
 
-  def keg_only_text
-    return unless f.keg_only?
-
-    s = <<~EOS
-      This formula is keg-only, which means it was not symlinked into #{HOMEBREW_PREFIX},
-      because #{f.keg_only_reason.to_s.chomp}.
-    EOS
-    if f.bin.directory? || f.sbin.directory?
-      s << "\nIf you need to have this software first in your PATH run:\n"
-      if f.bin.directory?
-        s << "  #{Utils::Shell.prepend_path_in_profile(f.opt_bin.to_s)}\n"
-      end
-      if f.sbin.directory?
-        s << "  #{Utils::Shell.prepend_path_in_profile(f.opt_sbin.to_s)}\n"
-      end
-    end
-
-    if f.lib.directory? || f.include.directory?
-      s << "\nFor compilers to find this software you may need to set:\n"
-      s << "    LDFLAGS:  -L#{f.opt_lib}\n" if f.lib.directory?
-      s << "    CPPFLAGS: -I#{f.opt_include}\n" if f.include.directory?
-      if which("pkg-config", ENV["HOMEBREW_PATH"]) &&
-         ((f.lib/"pkgconfig").directory? || (f.share/"pkgconfig").directory?)
-        s << "For pkg-config to find this software you may need to set:\n"
-        s << "    PKG_CONFIG_PATH: #{f.opt_lib}/pkgconfig\n" if (f.lib/"pkgconfig").directory?
-        s << "    PKG_CONFIG_PATH: #{f.opt_share}/pkgconfig\n" if (f.share/"pkgconfig").directory?
-      end
-    end
-    s << "\n"
-  end
-
   def function_completion_caveats(shell)
     return unless keg
     return unless which(shell.to_s, ENV["HOMEBREW_PATH"])

Library/Homebrew/cmd/--env.rb

@@ -37,7 +37,9 @@ module Homebrew
     if shell.nil?
       dump_build_env ENV
     else
-      env_keys.each { |key| puts Utils::Shell.export_value(shell, key, ENV[key]) }
+      env_keys.each do |key|
+        puts Utils::Shell.export_value(key, ENV[key], shell)
+      end
     end
   end
 end

Library/Homebrew/cmd/link.rb

@@ -13,6 +13,7 @@
 #:    If `--force` (or `-f`) is passed, Homebrew will allow keg-only formulae to be linked.
 
 require "ostruct"
+require "caveats"
 
 module Homebrew
   module_function
@@ -52,14 +53,16 @@ module Homebrew
 
       if keg_only
         if HOMEBREW_PREFIX.to_s == "/usr/local"
-          if keg.to_formula.keg_only_reason.reason == :provided_by_macos &&
+          f = keg.to_formula
+          caveats = Caveats.new(f)
+
+          if f.keg_only_reason.reason == :provided_by_macos &&
              (MacOS.version >= :mojave ||
               MacOS::Xcode.version >= "10.0" ||
               MacOS::CLT.version >= "10.0")
             opoo <<~EOS
               Refusing to link macOS-provided software: #{keg.name}
-              Instead, pass the full include/library paths to your compiler e.g.:
-                -I#{HOMEBREW_PREFIX}/opt/#{keg.name}/include -L#{HOMEBREW_PREFIX}/opt/#{keg.name}/lib
+              #{caveats.keg_only_text(skip_reason: true).strip}
             EOS
             next
           end
@@ -69,8 +72,7 @@ module Homebrew
               Refusing to link: #{keg.name}
               Linking keg-only #{keg.name} means you may end up linking against the insecure,
               deprecated system OpenSSL while using the headers from Homebrew's #{keg.name}.
-              Instead, pass the full include/library paths to your compiler e.g.:
-                -I#{HOMEBREW_PREFIX}/opt/#{keg.name}/include -L#{HOMEBREW_PREFIX}/opt/#{keg.name}/lib
+              #{caveats.keg_only_text(skip_reason: true).strip}
             EOS
             next
           end

Library/Homebrew/utils/shell.rb

@@ -21,7 +21,7 @@ module Utils
     end
 
     # quote values. quoting keys is overkill
-    def export_value(shell, key, value)
+    def export_value(key, value, shell = preferred)
       case shell
       when :bash, :ksh, :sh, :zsh
         "export #{key}=\"#{sh_quote(value)}\""