commit https://github.com/vim/vim/commit/d0232917ced39ff4838665fbcf379d5116a91aa3 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Jan 17 16:15:32 2016 +0100 patch 7.4.1115 Problem: MS-Windows: make clean in testdir doesn't clean everything. Solution: Add command to delete X* directories. (Ken Takata)

" Settings for test script execution
" Always use "COMMAND.COM", don't use the value of "$SHELL".
set shell=c:\COMMAND.COM shellquote= shellxquote= shellcmdflag=/c shellredir=>
" This is used only when the +eval feature is available.
if executable("cmd.exe")
   set shell=cmd.exe
endif