Bug 1363146 - tell people to install gyp if it's not installed, r=tta…

…ubert

Differential Revision: https://nss-review.dev.mozaws.net/D306

--HG--
extra : amend_source : 51ff39661bcec9247f88696190e576e013fd5bea

build.sh

@@ -183,7 +183,10 @@ if [[ "$rebuild_nspr" = 1 && "$no_local_nspr" = 0 ]]; then
     mv -f "$nspr_config".new "$nspr_config"
 fi
 if [ "$rebuild_gyp" = 1 ]; then
-
+    if ! hash gyp 2> /dev/null; then
+        echo "Please install gyp" 1>&2
+        exit 1
+    fi
     # These extra arguments aren't used in determining whether to rebuild.
     obj_dir="$dist_dir"/$target
     gyp_params+=(-Dnss_dist_obj_dir=$obj_dir)