fixup! Try to get rid of eval

Author: pirj

script/custom_build_functions.sh

@@ -1,6 +1,6 @@
 function run_cukes {
   if is_mri_192_plus; then
-    eval "(unset RUBYOPT; exec bin/rake acceptance --trace)"
+    RUBYOPT='' bin/rake acceptance --trace
     return $?
   elif is_jruby; then
     bin/rake smoke:app