$title Check that gams works with COMSPEC unset (CALL5,SEQ=660)

$onText
If COMSPEC is not set, we have some logic in GAMS/Base to keep things
rolling when we execute a subshell.  Check that this really works.

Contributor: Steve
$offText

$dropEnv COMSPEC
$call gams ? lo=0
$if errorlevel 1 $abort '$call gams  failed with COMSPEC unset'