bin/brew: whitelist http_proxy.

Fixes #3494.

1 files changed, 1 insertions, 1 deletions

diff --git a/bin/brew b/bin/brew
index f058fa34f..4b5488a45 100755
--- a/bin/brew
+++ b/bin/brew
@@ -88,7 +88,7 @@ then
   PATH="/usr/bin:/bin:/usr/sbin:/sbin"
 
   FILTERED_ENV=()
-  for VAR in HOME SHELL PATH TERM LOGNAME USER CI TRAVIS \
+  for VAR in HOME SHELL PATH TERM LOGNAME USER CI TRAVIS http_proxy \
              "${!HOMEBREW_@}" "${!TRAVIS_@}" "${!JENKINS_@}"
   do
     # Skip if variable value is empty.