patch 7.4.2167
Problem:    Small build can't run tests.
Solution:   Don't try setting 'packpath'.
diff --git a/src/testdir/setup.vim b/src/testdir/setup.vim
index dee3de2..a028401 100644
--- a/src/testdir/setup.vim
+++ b/src/testdir/setup.vim
@@ -2,7 +2,9 @@
 
 " Make sure 'runtimepath' and 'packpath' does not include $HOME.
 set rtp=$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after
-let &packpath = &rtp
+if has('packages')
+  let &packpath = &rtp
+endif
 
 " Only when the +eval feature is present. 
 if 1