patch 7.4.1687
Problem:    The channel close_cb option does not work.
Solution:   Use jo_close_partial instead of jo_err_partial. (Damien)
diff --git a/src/channel.c b/src/channel.c
index 98bc6be..b21c443 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -1103,7 +1103,7 @@
 	    *cbp = vim_strsave(opt->jo_close_cb);
 	else
 	    *cbp = NULL;
-	*pp = opt->jo_err_partial;
+	*pp = opt->jo_close_partial;
 	if (*pp != NULL)
 	    ++(*pp)->pt_refcount;
     }