diff -ur qtwebengine-opensource-src-5.9.0/src/buildtools/gn.pro qtwebengine-opensource-src-5.9.0-gn-bootstrap-verbose/src/buildtools/gn.pro

--- qtwebengine-opensource-src-5.9.0/src/buildtools/gn.pro	2017-05-19 06:22:04.000000000 +0200

+++ qtwebengine-opensource-src-5.9.0-gn-bootstrap-verbose/src/buildtools/gn.pro	2017-06-10 15:24:55.426814326 +0200

@@ -20,7 +20,7 @@

             src_3rd_party_dir = $$absolute_path("$${getChromiumSrcDir()}/../", "$$QTWEBENGINE_ROOT")

             gn_bootstrap = $$system_path($$absolute_path(chromium/tools/gn/bootstrap/bootstrap.py, $$src_3rd_party_dir))

             gn_args = $$system_quote($$gn_args)

-            gn_configure = $$system_quote($$gn_bootstrap) --shadow --gn-gen-args=$$gn_args $$ninja_path

+            gn_configure = $$system_quote($$gn_bootstrap) --verbose --shadow --gn-gen-args=$$gn_args $$ninja_path

             !system("cd $$system_quote($$system_path($$dirname(out))) && $$pythonPathForSystem() $$gn_configure") {

                 error("GN build error!")

             }