Don't mess with stdout when writing build config to a file

Library/Homebrew/cmd/config.rb

@@ -91,39 +91,34 @@ module Homebrew
   end
 
   # we try to keep output minimal
-  def dump_build_config
-    puts "HOMEBREW_VERSION: #{HOMEBREW_VERSION}"
-    puts "HEAD: #{head}"
-    puts "HOMEBREW_PREFIX: #{HOMEBREW_PREFIX}" if HOMEBREW_PREFIX.to_s != "/usr/local"
-    puts "HOMEBREW_CELLAR: #{HOMEBREW_CELLAR}" if HOMEBREW_CELLAR.to_s != "#{HOMEBREW_PREFIX}/Cellar"
-    puts hardware
-    puts "OS X: #{MACOS_FULL_VERSION}-#{kernel}"
-    puts "Xcode: #{xcode}" if xcode
-    puts "CLT: #{clt}" if clt
+  def dump_build_config(f)
+    f.puts "HOMEBREW_VERSION: #{HOMEBREW_VERSION}"
+    f.puts "HEAD: #{head}"
+    f.puts "HOMEBREW_PREFIX: #{HOMEBREW_PREFIX}" if HOMEBREW_PREFIX.to_s != "/usr/local"
+    f.puts "HOMEBREW_CELLAR: #{HOMEBREW_CELLAR}" if HOMEBREW_CELLAR.to_s != "#{HOMEBREW_PREFIX}/Cellar"
+    f.puts hardware
+    f.puts "OS X: #{MACOS_FULL_VERSION}-#{kernel}"
+    f.puts "Xcode: #{xcode}" if xcode
+    f.puts "CLT: #{clt}" if clt
 
     ruby_version = MacOS.version >= "10.9" ? "2.0" : "1.8"
     if RUBY_VERSION[/\d\.\d/] != ruby_version
-      puts "#{RUBY_PATH}:\n  #{RUBY_VERSION}-#{RUBY_PATCHLEVEL}"
+      f.puts "#{RUBY_PATH}:\n  #{RUBY_VERSION}-#{RUBY_PATCHLEVEL}"
     end
 
     unless MacOS.compilers_standard?
-      puts "GCC-4.0: build #{gcc_40}" if gcc_40
-      puts "GCC-4.2: build #{gcc_42}" if gcc_42
-      puts "LLVM-GCC: build #{llvm}"  if llvm
-      puts "Clang: #{clang ? "#{clang} build #{clang_build}" : "N/A"}"
+      f.puts "GCC-4.0: build #{gcc_40}" if gcc_40
+      f.puts "GCC-4.2: build #{gcc_42}" if gcc_42
+      f.puts "LLVM-GCC: build #{llvm}"  if llvm
+      f.puts "Clang: #{clang ? "#{clang} build #{clang_build}" : "N/A"}"
     end
 
-    puts "MacPorts/Fink: #{macports_or_fink}" if macports_or_fink
-
-    puts "X11: #{describe_x11}"
+    f.puts "MacPorts/Fink: #{macports_or_fink}" if macports_or_fink
+    f.puts "X11: #{describe_x11}"
   end
 
-  def write_build_config f
-    stdout = $stdout
-    $stdout = f
-    Homebrew.dump_build_config
-  ensure
-    $stdout = stdout
+  def write_build_config(f)
+    Homebrew.dump_build_config(f)
   end
 
   def dump_verbose_config