none of the various render-* worked under linux, due to a platform-specific default in the way ps-setup works.

svn: r14678

collects/redex/private/pict.ss

@@ -454,6 +454,7 @@
   (let ([ps-setup (make-object ps-setup%)])
     (send ps-setup copy-from (current-ps-setup))
     (send ps-setup set-file filename)
+    (send ps-setup set-mode 'file)
     (parameterize ([current-ps-setup ps-setup])
       (make-object post-script-dc% #f #f))))