Merge pull request #800 from zmwangx/set-TMPDIR-TEMP-TMP-to-HOMEBREW_TEMP

config: set TMPDIR, TEMP and TMP to HOMEBREW_TEMP

Library/Homebrew/config.rb

@@ -35,6 +35,11 @@ HOMEBREW_LOGS = Pathname.new(ENV["HOMEBREW_LOGS"] || "~/Library/Logs/Homebrew/")
 # Must use /tmp instead of $TMPDIR because long paths break Unix domain sockets
 HOMEBREW_TEMP = Pathname.new(ENV.fetch("HOMEBREW_TEMP", "/tmp"))
 
+# Set common tmpdir environment variables to HOMEBREW_TEMP
+ENV["TMPDIR"] = HOMEBREW_TEMP
+ENV["TEMP"] = HOMEBREW_TEMP
+ENV["TMP"] = HOMEBREW_TEMP
+
 unless defined? HOMEBREW_LIBRARY_PATH
   # Root of the Homebrew code base
   HOMEBREW_LIBRARY_PATH = Pathname.new(__FILE__).realpath.parent