cuirass: Line-buffer stdout and stderr.

* bin/cuirass.in (main): Add 'setvbuf' calls.

bin/cuirass.in

@@ -77,6 +77,11 @@ exec ${GUILE:-@GUILE@} --no-auto-compile -e main -s "$0" "$@"
 ;;;
 
 (define* (main #:optional (args (command-line)))
+
+  ;; Always have stdout/stderr line-buffered.
+  (setvbuf (current-output-port) _IOLBF)
+  (setvbuf (current-error-port) _IOLBF)
+
   (let ((opts (getopt-long args %options)))
     (parameterize
         ((%program-name     (car args))