patch 7.4.1324
Problem:    Channels with pipes don't work on MS-Windows.
Solution:   Add pipe I/O support. (Yasuhiro Matsumoto)
diff --git a/src/testdir/test_channel.vim b/src/testdir/test_channel.vim
index 5b78121..339db45 100644
--- a/src/testdir/test_channel.vim
+++ b/src/testdir/test_channel.vim
@@ -280,7 +280,7 @@
 endfunc
 
 func Test_pipe()
-  if !has('job') || !has('unix')
+  if !has('job')
     return
   endif
   let job = job_start("python test_channel_pipe.py")