Work around japaric/xargo#186 temporarily

alexcrichton · alexcrichton · commit cc9a70f61ca1 · 2017-12-26T12:20:17.000-08:00
diff --git a/ci/run.sh b/ci/run.sh
@@ -1,5 +1,8 @@
 set -ex
 
+# FIXME(japarix/xargo#186) this shouldn't be necessary
+export RUST_TARGET_PATH=`pwd`
+
 case $1 in
     thumb*)
         cargo=xargo
