Scupper sourceable output if brew install is piped

`brew install > file` should not give "export CC=/foo" output on Build Failures.

Also moved the "Using clang" output to brew when BuildError is thrown as that is where it is interesting, and not if you just do `brew --env`.

1 files changed, 3 insertions, 0 deletions

diff --git a/bin/brew b/bin/brew
index e3539c4ae..462f6328b 100755
--- a/bin/brew
+++ b/bin/brew
@@ -118,6 +118,9 @@ rescue BuildError => e
   ohai "Environment"
   puts Homebrew.config_s
   ohai "Build Flags"
+  puts %["--use-clang" was specified] if ARGV.include? '--use-clang'
+  puts %["--use-llvm" was specified] if ARGV.include? '--use-llvm'
+  puts %["--use-gcc" was specified] if ARGV.include? '--use-gcc'
   Homebrew.dump_build_env e.env
   puts
   onoe e