It is controlled by the +c argument. 

On Tuesday, June 23, 2015, Robert Goldman <rpgoldman@sift.net> wrote:

I'm having some real oddities testing on Windows.  Attached is a roster
of the implementations for which I see test failures -- the Allegro
variants and clisp.

Two oddities:

1. I do not get verbose output showing what happens when the tests fail.
 Critical information is missing from the logfiles.  I suspect that the
test script assumes that standard output is redirectable in some way
that it is not on Windows.  See allegro-test.txt which is attached.  Any
idea how to get the lisp output?  Any chance that REDIRECT-OUTPUTS
function from script-support.lisp does not work on Allegro + Windows?

2. I get fewer failures running one test at a time than running them all
in make.

Allegro testing reported the following:

-#---------------------------------------
Using g:/windows/allegro/32/non-smp/alisp
Ran 56 tests:
  52 passing and 4 failing
failing test(s):  test-encodings.script test-program.script
test-try-refinding.script test-utilities.script
-#---------------------------------------

But when I run the tests individually, only test-program and
test-utilities failed.  The other two tests succeeded.

I have rarely seen something like this before in make on Unix variants
due to not cleaning up the filesystem, but never in such a wholesale way.

----

Trying not to be a Unix bigot, but failing....

Best,
R