src/Pure/Admin/ci_profile.scala

--- a/src/Pure/Admin/ci_profile.scala	Sun Feb 26 23:50:19 2017 +0100
+++ b/src/Pure/Admin/ci_profile.scala	Mon Feb 27 00:00:28 2017 +0100
@@ -92,7 +92,7 @@
 
     val options =
       with_documents(Options.init())
-        .int.update("parallel_proofs", 2)
+        .int.update("parallel_proofs", 1)
         .int.update("threads", threads)
 
     print_section("BUILD")