@@ -94,9 +94,9 @@ function pip_install {

     $xtrace

     $sudo_pip \

-        http_proxy=${http_proxy:-} \

-        https_proxy=${https_proxy:-} \

-        no_proxy=${no_proxy:-} \

+        http_proxy="${http_proxy:-}" \

+        https_proxy="${https_proxy:-}" \

+        no_proxy="${no_proxy:-}" \

         PIP_FIND_LINKS=$PIP_FIND_LINKS \

         $cmd_pip install \

         $@